Fix undefined property warning

src/Response.php

@@ -6,52 +6,52 @@ class Response
 {
     # The actual Guzzle response:
     private $response;
-    
+
     # Core response:
     private $headers;
     private $bodyRaw;
     private $body;
-    
+
     # Properties:
     private $statusCode;
     private $timestamp;
     private $baseCurrency;
-    
+
     private $rates = [ ];
-    
+
     function __construct( \GuzzleHttp\Psr7\Response $response = null )
     {
         $this->response = $response;
-        
+
         $this->headers    = $response->getHeaders();
         $this->bodyRaw    = (string) $response->getBody();
         $this->body       = json_decode( $this->bodyRaw );
-        
+
         # Set our properties:
         $this->statusCode   = $response->getStatusCode();
-        $this->timestamp    = $this->body->timestamp;
+        $this->timestamp    = $this->body->timestamp ?? null;
         $this->baseCurrency = $this->body->source;
         $this->rates        = $this->body->quotes;
     }
-    
+
     /****************************/
     /*                          */
     /*         GETTERS          */
     /*                          */
     /****************************/
-    
+
     # Get the status code:
     public function getStatusCode()
     {
         return (int) $this->statusCode;
     }
-    
+
     # Get the timestamp of the request:
     public function getTimestamp()
     {
         return $this->timestamp;
     }
-    
+
     # Get the base currency:
     public function getBaseCurrency()
     {
@@ -64,26 +64,26 @@ public function getRates()
         # Convert the rates to a key / value array:
         return json_decode( json_encode($this->rates), true );
     }
-    
+
     # Return a specific rate:
     public function getRate( $code = null )
     {
         $rates = $this->getRates();
-        
+
         # If there's only one rate, and the code is null, return the first one:
         if( count($rates) == 1 && $code == null )
         {
             return reset( $rates );
         }
-        
+
         if( $this->body->rates->{$code} )
         {
             return $this->body->rates->{$code};
         }
-        
+
         return null;
     }
-    
+
     # Convert the response to JSON:
     public function toJSON()
     {
@@ -94,4 +94,4 @@ public function toJSON()
             'rates'        => $this->getRates()
         ]);
     }
-}
+}