diff --git a/CHANGELOG.md b/CHANGELOG.md
index b77af38..54a056f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,33 @@ you can use the following url: https://github.com/ericsizemore/pagination/compar
 
 Simply replace the version numbers depending on which set of changes you wish to see.
 
+### 2.0.1 (2024-03-02)
+
+Mostly small coding standard (CS) related changes, with some improvements to method docblocks throughout.
+
+#### Changed
+
+  * Bumped version to `2.0.1`.
+  * Small change to how `$pagesInRange` within `paginate()` is determined.
+  * (CS) Rearranged the order of methods within `Paginator` and `PaginatorInterface`.
+  * Made the following helper functions static:
+    * `determinePageRange()`
+    * `determinePreviousPageNumber()`
+    * `determineNextPageNumber()`
+  * Updated `composer.lock`
+
+#### Added
+
+  * Added validation to `Paginator`'s construct for the passed `$config` parameter.
+    * Uses a new helper function `validateConfig()`, which is a static protected method.
+  * Added some documentation/docblocks throughout, mostly to the `PaginatorInterface`.
+  * Added `ext-pdo` and `ext-pdo_sqlite` to the composer require-dev.
+  * Added the `Override` attribute to `Paginator` methods that are from `PaginatorInterface`.
+
+#### Removed
+
+  * None
+
 
 ### 2.0.0 (2024-02-28)
 
diff --git a/composer.json b/composer.json
index 1867939..3cd8d9d 100644
--- a/composer.json
+++ b/composer.json
@@ -38,6 +38,8 @@
         "php": "^8.2 <8.5"
     },
     "require-dev": {
+        "ext-pdo": "*",
+        "ext-pdo_sqlite": "*",
         "friendsofphp/php-cs-fixer": "dev-master",
         "phpstan/phpstan": "^1.11",
         "phpstan/phpstan-phpunit": "^1.4",
@@ -66,4 +68,4 @@
         "phpstan": "vendor/bin/phpstan analyse -c phpstan.neon",
         "test": "phpunit"
     }
-}
\ No newline at end of file
+}
diff --git a/composer.lock b/composer.lock
index 7b8bc29..e5ddd18 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "098dfe02a56336ea5659c2d6a0b4c9dd",
+    "content-hash": "4096712e5c0afbfde8eac82d6b4116a1",
     "packages": [],
     "packages-dev": [
         {
@@ -233,12 +233,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/PHP-CS-Fixer/PHP-CS-Fixer.git",
-                "reference": "1543a7a0ce3f08e4e074db0c7c1697bbe9ea2615"
+                "reference": "438d5eac73bdd50164dded5f0048526ab078c4e4"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/PHP-CS-Fixer/PHP-CS-Fixer/zipball/1543a7a0ce3f08e4e074db0c7c1697bbe9ea2615",
-                "reference": "1543a7a0ce3f08e4e074db0c7c1697bbe9ea2615",
+                "url": "https://api.github.com/repos/PHP-CS-Fixer/PHP-CS-Fixer/zipball/438d5eac73bdd50164dded5f0048526ab078c4e4",
+                "reference": "438d5eac73bdd50164dded5f0048526ab078c4e4",
                 "shasum": ""
             },
             "require": {
@@ -318,7 +318,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2024-02-27T22:15:52+00:00"
+            "time": "2024-02-28T19:50:58+00:00"
         },
         {
             "name": "myclabs/deep-copy",
@@ -565,12 +565,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "7d6943daa4e3b247f18f7d8bb860d8f2ca41e3bf"
+                "reference": "d9430ff06660959d9fd659b65acc2236e02cd850"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/7d6943daa4e3b247f18f7d8bb860d8f2ca41e3bf",
-                "reference": "7d6943daa4e3b247f18f7d8bb860d8f2ca41e3bf",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/d9430ff06660959d9fd659b65acc2236e02cd850",
+                "reference": "d9430ff06660959d9fd659b65acc2236e02cd850",
                 "shasum": ""
             },
             "require": {
@@ -620,7 +620,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2024-02-27T20:14:47+00:00"
+            "time": "2024-03-01T14:22:19+00:00"
         },
         {
             "name": "phpstan/phpstan-phpunit",
@@ -1059,12 +1059,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "3efde166f8370f1620a72f72c0c996a035cfe1f7"
+                "reference": "c7095e9ada364041de8da7208c31ab1c37ec9c45"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/3efde166f8370f1620a72f72c0c996a035cfe1f7",
-                "reference": "3efde166f8370f1620a72f72c0c996a035cfe1f7",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/c7095e9ada364041de8da7208c31ab1c37ec9c45",
+                "reference": "c7095e9ada364041de8da7208c31ab1c37ec9c45",
                 "shasum": ""
             },
             "require": {
@@ -1152,7 +1152,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2024-02-27T08:26:57+00:00"
+            "time": "2024-03-01T17:07:45+00:00"
         },
         {
             "name": "psr/container",
@@ -3596,6 +3596,9 @@
     "platform": {
         "php": "^8.2 <8.5"
     },
-    "platform-dev": [],
+    "platform-dev": {
+        "ext-pdo": "*",
+        "ext-pdo_sqlite": "*"
+    },
     "plugin-api-version": "2.6.0"
 }
diff --git a/src/Exception/CallbackInvalidException.php b/src/Exception/CallbackInvalidException.php
index 5c23feb..a3ab0c0 100644
--- a/src/Exception/CallbackInvalidException.php
+++ b/src/Exception/CallbackInvalidException.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
diff --git a/src/Exception/CallbackNotFoundException.php b/src/Exception/CallbackNotFoundException.php
index 7906a1f..bdfb86a 100644
--- a/src/Exception/CallbackNotFoundException.php
+++ b/src/Exception/CallbackNotFoundException.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
diff --git a/src/Exception/InvalidPageNumberException.php b/src/Exception/InvalidPageNumberException.php
index c459833..7fa1753 100644
--- a/src/Exception/InvalidPageNumberException.php
+++ b/src/Exception/InvalidPageNumberException.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
diff --git a/src/Pagination.php b/src/Pagination.php
index 50bd183..88d3499 100644
--- a/src/Pagination.php
+++ b/src/Pagination.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
@@ -48,48 +48,86 @@
 use function count;
 
 /**
- * Class Pagination
+ * Pagination class.
  *
  * @implements IteratorAggregate<(int|string), int>
  */
 class Pagination implements IteratorAggregate, Countable
 {
     /**
+     * Item collection.
+     *
      * @var array<int>
      */
     private array $items = [];
 
     /**
+     * Page collection.
+     *
      * @var array<int>
      */
     private array $pages = [];
 
+    /**
+     * Total number of pages for the item collection.
+     */
     private int $totalNumberOfPages;
 
+    /**
+     * Current page number of item collection.
+     */
     private int $currentPageNumber;
 
+    /**
+     * First page number of item collection.
+     */
     private int $firstPageNumber;
 
+    /**
+     * Last page number of item collection.
+     */
     private int $lastPageNumber;
 
+    /**
+     * Previous page number. Will be null if on the first page.
+     */
     private ?int $previousPageNumber = null;
 
+    /**
+     * Next page number. Will be null if on the last page.
+     */
     private ?int $nextPageNumber = null;
 
+    /**
+     * Currently set amount of items we want per page.
+     */
     private int $itemsPerPage;
 
+    /**
+     * Total number of items in the collection.
+     */
     private int $totalNumberOfItems;
 
+    /**
+     * Given a page range, first page number.
+     */
     private int $firstPageNumberInRange;
 
+    /**
+     * Given a page range, last page number.
+     */
     private int $lastPageNumberInRange;
 
     /**
+     * Optional meta data to include with pagination.
+     *
      * @var array<int|string, string>|array<mixed>
      */
     private array $meta;
 
     /**
+     * Returns the current collection.
+     *
      * @return array<int>
      */
     public function getItems(): array
@@ -98,11 +136,14 @@ public function getItems(): array
     }
 
     /**
+     * Sets the item collection to be paginated.
+     *
      * @param array<int> $items
      */
     public function setItems(array $items): static
     {
         $this->items = $items;
+
         return $this;
     }
 
@@ -114,6 +155,7 @@ public function getCurrentPageNumber(): int
     public function setCurrentPageNumber(int $currentPageNumber): static
     {
         $this->currentPageNumber = $currentPageNumber;
+
         return $this;
     }
 
@@ -125,6 +167,7 @@ public function getFirstPageNumber(): int
     public function setFirstPageNumber(int $firstPageNumber): static
     {
         $this->firstPageNumber = $firstPageNumber;
+
         return $this;
     }
 
@@ -136,6 +179,7 @@ public function getFirstPageNumberInRange(): int
     public function setFirstPageNumberInRange(int $firstPageNumberInRange): static
     {
         $this->firstPageNumberInRange = $firstPageNumberInRange;
+
         return $this;
     }
 
@@ -147,6 +191,7 @@ public function getItemsPerPage(): int
     public function setItemsPerPage(int $itemsPerPage): static
     {
         $this->itemsPerPage = $itemsPerPage;
+
         return $this;
     }
 
@@ -158,6 +203,7 @@ public function getLastPageNumber(): int
     public function setLastPageNumber(int $lastPageNumber): static
     {
         $this->lastPageNumber = $lastPageNumber;
+
         return $this;
     }
 
@@ -169,6 +215,7 @@ public function getLastPageNumberInRange(): int
     public function setLastPageNumberInRange(int $lastPageNumberInRange): static
     {
         $this->lastPageNumberInRange = $lastPageNumberInRange;
+
         return $this;
     }
 
@@ -180,6 +227,7 @@ public function getNextPageNumber(): ?int
     public function setNextPageNumber(?int $nextPageNumber): static
     {
         $this->nextPageNumber = $nextPageNumber;
+
         return $this;
     }
 
@@ -197,6 +245,7 @@ public function getPages(): array
     public function setPages(array $pages): static
     {
         $this->pages = $pages;
+
         return $this;
     }
 
@@ -208,6 +257,7 @@ public function getPreviousPageNumber(): ?int
     public function setPreviousPageNumber(?int $previousPageNumber): static
     {
         $this->previousPageNumber = $previousPageNumber;
+
         return $this;
     }
 
@@ -219,6 +269,7 @@ public function getTotalNumberOfItems(): int
     public function setTotalNumberOfItems(int $totalNumberOfItems): static
     {
         $this->totalNumberOfItems = $totalNumberOfItems;
+
         return $this;
     }
 
@@ -230,6 +281,7 @@ public function getTotalNumberOfPages(): int
     public function setTotalNumberOfPages(int $totalNumberOfPages): static
     {
         $this->totalNumberOfPages = $totalNumberOfPages;
+
         return $this;
     }
 
@@ -265,6 +317,7 @@ public function getMeta(): array
     public function setMeta(array $meta): static
     {
         $this->meta = $meta;
+
         return $this;
     }
 }
diff --git a/src/Paginator.php b/src/Paginator.php
index ce76733..7814423 100644
--- a/src/Paginator.php
+++ b/src/Paginator.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
@@ -46,15 +46,21 @@
 use Esi\Pagination\Exception\InvalidPageNumberException;
 use Iterator;
 
+use function array_filter;
 use function ceil;
+use function in_array;
+use function is_int;
 use function iterator_to_array;
 use function max;
 use function min;
 use function range;
 use function sprintf;
 
+use const ARRAY_FILTER_USE_BOTH;
+
 /**
- * Class Paginator
+ * Main Paginator Class.
+ *
  * @see \Esi\Pagination\Tests\PaginatorTest
  */
 class Paginator implements PaginatorInterface
@@ -62,12 +68,12 @@ class Paginator implements PaginatorInterface
     /**
      * A callback that is used to determine the total number of items in your collection (returned as an integer).
      */
-    private ?Closure $itemTotalCallback   = null;
+    private ?Closure $itemTotalCallback = null;
 
     /**
      * A callback to slice your collection given an offset and length argument.
      */
-    private ?Closure $sliceCallback       = null;
+    private ?Closure $sliceCallback = null;
 
     /**
      * A callback to run before the count and slice queries.
@@ -77,7 +83,7 @@ class Paginator implements PaginatorInterface
     /**
      * A callback to run after the count and slice queries.
      */
-    private ?Closure $afterQueryCallback  = null;
+    private ?Closure $afterQueryCallback = null;
 
     /**
      * Number of items to include per page.
@@ -85,6 +91,7 @@ class Paginator implements PaginatorInterface
     private int $itemsPerPage = 10;
 
     /**
+     * Number of pages in range.
      */
     private int $pagesInRange = 5;
 
@@ -92,7 +99,7 @@ class Paginator implements PaginatorInterface
      * Constructor - passing optional configuration
      *
      * <code>
-     * $paginator = new Paginator(array(
+     * $paginator = new Paginator([
      *     'itemTotalCallback' => function () {
      *         // ...
      *     },
@@ -100,8 +107,8 @@ class Paginator implements PaginatorInterface
      *         // ...
      *     },
      *     'itemsPerPage' => 10,
-     *     'pagesInRange' => 5
-     * ));
+     *     'pagesInRange' => 5,
+     * ]);
      * </code>
      *
      * @param null|array{}|array{
@@ -113,17 +120,22 @@ class Paginator implements PaginatorInterface
      */
     public function __construct(?array $config = null)
     {
-        if ($config !== null && $config !== []) {
-            $this->setItemTotalCallback($config['itemTotalCallback']);
-            $this->setSliceCallback($config['sliceCallback']);
-            $this->setItemsPerPage($config['itemsPerPage']);
-            $this->setPagesInRange($config['pagesInRange']);
+        $config = self::validateConfig($config);
+
+        if ($config === []) {
+            return;
         }
+
+        $this->setItemTotalCallback($config['itemTotalCallback']);
+        $this->setSliceCallback($config['sliceCallback']);
+        $this->setItemsPerPage($config['itemsPerPage']);
+        $this->setPagesInRange($config['pagesInRange']);
     }
 
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function paginate(int $currentPageNumber = 1): Pagination
     {
         if ($this->itemTotalCallback === null) {
@@ -146,9 +158,7 @@ public function paginate(int $currentPageNumber = 1): Pagination
 
         $sliceCallback       = $this->sliceCallback;
         $itemTotalCallback   = $this->itemTotalCallback;
-        /** @var Closure $beforeQueryCallback */
         $beforeQueryCallback = $this->prepareBeforeQueryCallback();
-        /** @var Closure $afterQueryCallback  */
         $afterQueryCallback  = $this->prepareAfterQueryCallback();
 
         $pagination = new Pagination();
@@ -158,8 +168,8 @@ public function paginate(int $currentPageNumber = 1): Pagination
         $afterQueryCallback($this, $pagination);
 
         $numberOfPages = (int) ceil($totalNumberOfItems / $this->itemsPerPage);
-        $pagesInRange  = $this->pagesInRange > $numberOfPages ? $numberOfPages : $this->pagesInRange;
-        $pages         = $this->determinePageRange($currentPageNumber, $pagesInRange, $numberOfPages);
+        $pagesInRange  = min($this->pagesInRange, $numberOfPages);
+        $pages         = self::determinePageRange($currentPageNumber, $pagesInRange, $numberOfPages);
         $offset        = ($currentPageNumber - 1) * $this->itemsPerPage;
 
         $beforeQueryCallback($this, $pagination);
@@ -176,8 +186,8 @@ public function paginate(int $currentPageNumber = 1): Pagination
 
         $afterQueryCallback($this, $pagination);
 
-        $previousPageNumber = $this->determinePreviousPageNumber($currentPageNumber);
-        $nextPageNumber     = $this->determineNextPageNumber($currentPageNumber, $numberOfPages);
+        $previousPageNumber = self::determinePreviousPageNumber($currentPageNumber);
+        $nextPageNumber     = self::determineNextPageNumber($currentPageNumber, $numberOfPages);
 
         /** @var non-empty-array<int> $pages **/
         $pagination
@@ -201,17 +211,19 @@ public function paginate(int $currentPageNumber = 1): Pagination
     /**
      * {@inheritdoc}
      */
-    public function getSliceCallback(): ?Closure
+    #[\Override]
+    public function getItemTotalCallback(): ?Closure
     {
-        return $this->sliceCallback;
+        return $this->itemTotalCallback;
     }
 
     /**
      * {@inheritdoc}
      */
-    public function setSliceCallback(?Closure $sliceCallback): static
+    #[\Override]
+    public function setItemTotalCallback(?Closure $itemTotalCallback): static
     {
-        $this->sliceCallback = $sliceCallback;
+        $this->itemTotalCallback = $itemTotalCallback;
 
         return $this;
     }
@@ -219,14 +231,27 @@ public function setSliceCallback(?Closure $sliceCallback): static
     /**
      * {@inheritdoc}
      */
-    public function getItemTotalCallback(): ?Closure
+    #[\Override]
+    public function getSliceCallback(): ?Closure
     {
-        return $this->itemTotalCallback;
+        return $this->sliceCallback;
     }
 
     /**
      * {@inheritdoc}
      */
+    #[\Override]
+    public function setSliceCallback(?Closure $sliceCallback): static
+    {
+        $this->sliceCallback = $sliceCallback;
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    #[\Override]
     public function getBeforeQueryCallback(): ?Closure
     {
         return $this->beforeQueryCallback;
@@ -235,6 +260,7 @@ public function getBeforeQueryCallback(): ?Closure
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function setBeforeQueryCallback(?Closure $beforeQueryCallback): static
     {
         $this->beforeQueryCallback = $beforeQueryCallback;
@@ -245,6 +271,7 @@ public function setBeforeQueryCallback(?Closure $beforeQueryCallback): static
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function getAfterQueryCallback(): ?Closure
     {
         return $this->afterQueryCallback;
@@ -253,6 +280,7 @@ public function getAfterQueryCallback(): ?Closure
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function setAfterQueryCallback(?Closure $afterQueryCallback): static
     {
         $this->afterQueryCallback = $afterQueryCallback;
@@ -263,16 +291,7 @@ public function setAfterQueryCallback(?Closure $afterQueryCallback): static
     /**
      * {@inheritdoc}
      */
-    public function setItemTotalCallback(?Closure $itemTotalCallback): static
-    {
-        $this->itemTotalCallback = $itemTotalCallback;
-
-        return $this;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
+    #[\Override]
     public function getItemsPerPage(): int
     {
         return $this->itemsPerPage;
@@ -281,6 +300,7 @@ public function getItemsPerPage(): int
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function setItemsPerPage(int $itemsPerPage): static
     {
         $this->itemsPerPage = $itemsPerPage;
@@ -291,6 +311,7 @@ public function setItemsPerPage(int $itemsPerPage): static
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function getPagesInRange(): int
     {
         return $this->pagesInRange;
@@ -299,6 +320,7 @@ public function getPagesInRange(): int
     /**
      * {@inheritdoc}
      */
+    #[\Override]
     public function setPagesInRange(int $pagesInRange): static
     {
         $this->pagesInRange = $pagesInRange;
@@ -306,9 +328,47 @@ public function setPagesInRange(int $pagesInRange): static
         return $this;
     }
 
-    // Helper functions to the main paginate() function.
+    /**
+     * Helper function for __construct() to validate the passed $config.
+     *
+     * @param null|array{}|array{
+     *     itemTotalCallback: Closure,
+     *     sliceCallback: Closure,
+     *     itemsPerPage: int,
+     *     pagesInRange: int
+     * } $config Expected array signature.
+     *
+     * @return array{}|array{
+     *     itemTotalCallback: Closure,
+     *     sliceCallback: Closure,
+     *     itemsPerPage: int,
+     *     pagesInRange: int
+     * }
+     */
+    protected static function validateConfig(?array $config = null): array
+    {
+        static $validKeys = ['itemTotalCallback', 'sliceCallback', 'itemsPerPage', 'pagesInRange'];
+
+        $config ??= [];
+
+        return array_filter($config, static function (mixed $value, string $key) use ($validKeys): bool {
+            if (!in_array($key, $validKeys, true)) {
+                return false;
+            }
+
+            return match($key) {
+                'itemTotalCallback', 'sliceCallback' => $value instanceof Closure,
+                default => is_int($value)
+            };
+        }, ARRAY_FILTER_USE_BOTH);
+
+    }
 
     /**
+     * A helper function to {@see self::paginate()}.
+     *
+     * Ensures the beforeQueryCallback is a valid Closure. If the currently set
+     * beforeQueryCallback is null, it will return an empty Closure object.
      */
     protected function prepareBeforeQueryCallback(): Closure
     {
@@ -320,6 +380,10 @@ protected function prepareBeforeQueryCallback(): Closure
     }
 
     /**
+     * A helper function to {@see self::paginate()}.
+     *
+     * Ensures the afterQueryCallback is a valid Closure. If the currently set
+     * afterQueryCallback is null, it will return an empty Closure object.
      */
     protected function prepareAfterQueryCallback(): Closure
     {
@@ -331,9 +395,14 @@ protected function prepareAfterQueryCallback(): Closure
     }
 
     /**
+     * A helper function to {@see self::paginate()}.
+     *
+     * Determines the number of pages in range given the current page number, currently
+     * set pages in range, and total number of pages.
+     *
      * @return array<int>
      */
-    protected function determinePageRange(int $currentPageNumber, int $pagesInRange, int $numberOfPages): array
+    protected static function determinePageRange(int $currentPageNumber, int $pagesInRange, int $numberOfPages): array
     {
         $change = (int) ceil($pagesInRange / 2);
 
@@ -352,28 +421,30 @@ protected function determinePageRange(int $currentPageNumber, int $pagesInRange,
     }
 
     /**
+     * A helper function to {@see self::paginate()}.
+     *
+     * Determines the previous page number based on the current page number.
      */
-    protected function determinePreviousPageNumber(int $currentPageNumber): ?int
+    protected static function determinePreviousPageNumber(int $currentPageNumber): ?int
     {
-        $previousPageNumber = null;
-
         if (($currentPageNumber - 1) > 0) {
-            $previousPageNumber = $currentPageNumber - 1;
+            return $currentPageNumber - 1;
         }
 
-        return $previousPageNumber;
+        return null;
     }
 
     /**
+     * A helper function to {@see self::paginate()}.
+     *
+     * Determines the next page number based on the current page number.
      */
-    protected function determineNextPageNumber(int $currentPageNumber, int $numberOfPages): ?int
+    protected static function determineNextPageNumber(int $currentPageNumber, int $numberOfPages): ?int
     {
-        $nextPageNumber = null;
-
         if (($currentPageNumber + 1) <= $numberOfPages) {
-            $nextPageNumber = $currentPageNumber + 1;
+            return $currentPageNumber + 1;
         }
 
-        return $nextPageNumber;
+        return null;
     }
 }
diff --git a/src/PaginatorInterface.php b/src/PaginatorInterface.php
index d3655b8..1ab992c 100644
--- a/src/PaginatorInterface.php
+++ b/src/PaginatorInterface.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
@@ -42,6 +42,7 @@
 namespace Esi\Pagination;
 
 use Closure;
+use Esi\Pagination\Exception\CallbackNotFoundException;
 use Esi\Pagination\Exception\InvalidPageNumberException;
 use InvalidArgumentException;
 
@@ -51,42 +52,89 @@
 interface PaginatorInterface
 {
     /**
-     * Run paginate algorithm using the current page number
+     * Run paginate algorithm using the current page number.
      *
-     * @param int $currentPageNumber Page number, usually passed from the current request
-     * @return Pagination Collection of items returned by the slice callback with pagination meta information
-     * @throws InvalidArgumentException
+     * @param   int         $currentPageNumber  Page number, usually passed from the current request.
+     * @return  Pagination                      Collection of items returned by the slice callback with pagination meta information.
+     *
+     * @throws CallbackNotFoundException
      * @throws InvalidPageNumberException
      */
     public function paginate(int $currentPageNumber = 1): Pagination;
 
-    public function getSliceCallback(): ?Closure;
+    /**
+     * Returns the currently assigned item total callback, or null if not set.
+     */
+    public function getItemTotalCallback(): ?Closure;
 
-    public function setSliceCallback(Closure $sliceCallback): PaginatorInterface;
+    /**
+     * Sets the item total callback. Used to determine the total number of items in your collection.
+     *
+     * This should be a Closure, and it would be expected to return an integer. For example:
+     *
+     * function() use($items): int {
+     *     return count($items);
+     * }
+     */
+    public function setItemTotalCallback(?Closure $itemTotalCallback): PaginatorInterface;
 
-    public function getItemTotalCallback(): ?Closure;
+    /**
+     * Returns the currently assigned slice callback, or null if not set.
+     */
+    public function getSliceCallback(): ?Closure;
 
-    public function setItemTotalCallback(Closure $itemTotalCallback): PaginatorInterface;
+    /**
+     * Sets the slice callback. Actually slices your collection given an **offset** and **length** argument.
+     *
+     * This should be a Closure, and it would be expected to return an array. For example:
+     *
+     * function (int $offset, int $length) use ($items): array {
+     *     return array_slice($items, $offset, $length);
+     * }
+     */
+    public function setSliceCallback(?Closure $sliceCallback): PaginatorInterface;
 
+    /**
+     * Returns the currently assigned before query callback, null if not set.
+     */
     public function getBeforeQueryCallback(): ?Closure;
 
-    public function setBeforeQueryCallback(Closure $beforeQueryCallback): PaginatorInterface;
+    /**
+     * Sets the before query callback. Called before the count and slice queries.
+     *
+     * This should be a Closure, and there is no real return or signature expectation.
+     */
+    public function setBeforeQueryCallback(?Closure $beforeQueryCallback): PaginatorInterface;
 
+    /**
+     * Returns the currently assigned after query callback, null if not set.
+     */
     public function getAfterQueryCallback(): ?Closure;
 
-    public function setAfterQueryCallback(Closure $afterQueryCallback): PaginatorInterface;
+    /**
+     * Sets the after query callback. Called after the count and slice queries.
+     *
+     * This should be a Closure, and there is no real return or signature expectation.
+     */
+    public function setAfterQueryCallback(?Closure $afterQueryCallback): PaginatorInterface;
 
+    /**
+     * Returns the number of items per page.
+     */
     public function getItemsPerPage(): int;
 
     /**
-     * @throws InvalidArgumentException
+     * Sets the number of items per page.
      */
     public function setItemsPerPage(int $itemsPerPage): PaginatorInterface;
 
+    /**
+     * Returns the number of pages in range.
+     */
     public function getPagesInRange(): int;
 
     /**
-     * @throws InvalidArgumentException
+     * Sets the number of pages in range.
      */
     public function setPagesInRange(int $pagesInRange): PaginatorInterface;
 }
diff --git a/tests/PaginatorTest.php b/tests/PaginatorTest.php
index d45b934..f5b0fdb 100644
--- a/tests/PaginatorTest.php
+++ b/tests/PaginatorTest.php
@@ -6,7 +6,7 @@
  * Pagination - Simple, lightweight and universal service that implements pagination on collections of things.
  *
  * @author    Eric Sizemore <admin@secondversion.com>
- * @version   2.0.0
+ * @version   2.0.1
  * @copyright (C) 2024 Eric Sizemore
  * @license   The MIT License (MIT)
  *
@@ -41,12 +41,13 @@
 
 namespace Esi\Pagination\Tests;
 
+use ArrayIterator;
 use Esi\Pagination\Exception\CallbackNotFoundException;
 use Esi\Pagination\Exception\InvalidPageNumberException;
 use Esi\Pagination\Pagination;
 use Esi\Pagination\Paginator;
 use PDO;
-use PDOException;
+use PDOStatement;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\Attributes\UsesClass;
 use PHPUnit\Framework\TestCase;
@@ -66,16 +67,55 @@
 #[UsesClass(InvalidPageNumberException::class)]
 class PaginatorTest extends TestCase
 {
+    /**
+     * Paginator object used throughout testing.
+     */
     protected Paginator $paginator;
 
+    /**
+     * PDO_SQLITE object for the database testing.
+     */
     protected static PDO $dbObj;
 
+    /**
+     * Creates our Paginator and PDO objects.
+     */
     protected function setUp(): void
     {
+        parent::setUp();
+
         $this->paginator = new Paginator();
         self::$dbObj     = new PDO(sprintf('sqlite:%s/fixtures/factbook.db', __DIR__));
     }
 
+    /**
+     */
+    public function testConstructionWithInvalidConfig(): void
+    {
+        // @phpstan-ignore-next-line
+        $paginator = new Paginator([
+            'itemTotalCallback' => '',
+            'sliceCallback'     => '',
+            'itemsPerPage'      => '',
+            'pagesInRange'      => '',
+            'nonexistent'       => '',
+        ]);
+
+        self::assertNull($paginator->getItemTotalCallback());
+        self::assertNull($paginator->getSliceCallback());
+        self::assertSame(10, $paginator->getItemsPerPage());
+        self::assertSame(5, $paginator->getPagesInRange());
+    }
+
+    /**
+     * Test pagination of database results. This test uses PDO and a SQLite db, though this is perfectly
+     * valid for MySQL, etc. as well.
+     *
+     * Uses factbook.db, which is licensed under the CC0-1.0 (public domain).
+     *
+     * @see https://github.com/factbook/factbook.sql/releases
+     * @see ../fixtures/factbook.db
+     */
     public function testPaginateDbResults(): void
     {
         $paginator = new Paginator();
@@ -84,7 +124,7 @@ public function testPaginateDbResults(): void
             ->setPagesInRange(5);
 
         $paginator->setItemTotalCallback(static function (): int {
-            /** @var \PDOStatement $result */
+            /** @var PDOStatement $result */
             $result = self::$dbObj->query("SELECT COUNT(*) as totalCount FROM facts");
             $row    = $result->fetchColumn();
             return (int) $row;
@@ -92,7 +132,7 @@ public function testPaginateDbResults(): void
 
         // Pass our slice callback.
         $paginator->setSliceCallback(static function (int $offset, int $length): array {
-            /** @var \PDOStatement $result */
+            /** @var PDOStatement $result */
             $result     = self::$dbObj->query(sprintf('SELECT name, area FROM facts ORDER BY area DESC LIMIT %d, %d', $offset, $length), PDO::FETCH_ASSOC);
             $collection = [];
 
@@ -103,7 +143,7 @@ public function testPaginateDbResults(): void
             return $collection;
         });
 
-        $pagination = $paginator->paginate(1);
+        $pagination = $paginator->paginate();
 
         self::assertNotEmpty($pagination->getItems());
         self::assertSame(261, $pagination->getTotalNumberOfItems());
@@ -366,7 +406,7 @@ public function testBeforeAndAfterQueryCallbacks(): void
         self::assertFalse($beforeQueryFired);
         self::assertFalse($afterQueryFired);
 
-        $paginator->paginate(1);
+        $paginator->paginate();
 
         self::assertTrue($beforeQueryFired); // @phpstan-ignore-line
         self::assertTrue($afterQueryFired); // @phpstan-ignore-line
@@ -392,7 +432,7 @@ public function testPaginateLowVolumeConstructorConfig(): void
             'pagesInRange'      => 5,
         ]);
 
-        $pagination = $paginator->paginate(1);
+        $pagination = $paginator->paginate();
 
         self::assertCount(10, $pagination->getItems());
         self::assertCount(3, $pagination->getPages());
@@ -458,7 +498,7 @@ public function testPaginationIteratorAggregate(): void
             'pagesInRange'      => 5,
         ]);
 
-        $pagination = $paginator->paginate(1);
+        $pagination = $paginator->paginate();
 
         self::assertCount(15, $pagination);
 
@@ -491,7 +531,7 @@ public function testPaginateLowVolume(): void
             return array_slice($items, $offset, $length);
         });
 
-        $pagination = $this->paginator->paginate(1);
+        $pagination = $this->paginator->paginate();
 
         self::assertContains('meta_1', $pagination->getMeta());
         self::assertContains('meta_2', $pagination->getMeta());
@@ -570,7 +610,7 @@ public function testPaginateHighVolume(): void
             return array_slice($items, $offset, $length);
         });
 
-        $pagination = $this->paginator->paginate(1);
+        $pagination = $this->paginator->paginate();
 
         self::assertContains('meta_3', $pagination->getMeta());
         self::assertContains('meta_4', $pagination->getMeta());
@@ -631,7 +671,7 @@ public function testPaginateHighVolume(): void
         self::assertContains('meta_4', $pagination->getMeta());
     }
 
-    public function testPaginateNegativeOne(): void
+    public function testPaginateItemsPerPageNegativeOne(): void
     {
         $items = range(0, 1000);
 
@@ -649,7 +689,7 @@ public function testPaginateNegativeOne(): void
             return array_slice($items, $offset, $length);
         });
 
-        $pagination = $this->paginator->paginate(1);
+        $pagination = $this->paginator->paginate();
 
         self::assertContains('meta_3', $pagination->getMeta());
         self::assertContains('meta_4', $pagination->getMeta());
@@ -716,12 +756,12 @@ public function testPaginationIterator(): void
 
         $paginator = new Paginator([
             'itemTotalCallback' => static fn (): int => count($items),
-            'sliceCallback'     => static fn (int $offset, int $length): \ArrayIterator => new \ArrayIterator(array_slice($items, $offset, $length)),
+            'sliceCallback'     => static fn (int $offset, int $length): ArrayIterator => new ArrayIterator(array_slice($items, $offset, $length)),
             'itemsPerPage'      => 15,
             'pagesInRange'      => 5,
         ]);
 
-        $pagination = $paginator->paginate(1);
+        $pagination = $paginator->paginate();
 
         self::assertCount(15, $pagination);
 
@@ -732,8 +772,6 @@ public function testPaginationIterator(): void
 
     public function testItemTotalCallbackNotFound(): void
     {
-        $items = range(0, 27);
-
         $this->paginator->setItemsPerPage(10)->setPagesInRange(5);
 
         $this->expectException(CallbackNotFoundException::class);
@@ -744,8 +782,6 @@ public function testItemTotalCallbackNotFound(): void
 
     public function testSliceCallbackNotFound(): void
     {
-        $items = range(0, 27);
-
         $this->paginator->setItemsPerPage(10)->setPagesInRange(5);
 
         $this->expectException(CallbackNotFoundException::class);