some violation I found in your project

[axv7014]

really good project, and I found some violaitons of your project that may cause a problem, you can take a look if you have free time QWQ
1.bug detect by checkstyle
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\CrawlerPack.java:94: At-clause should have a non-empty description. [NonEmptyAtclauseDescription]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\CrawlerPack.java:400: At-clause should have a non-empty description. [NonEmptyAtclauseDescription]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\CrawlerPack.java:401: At-clause should have a non-empty description. [NonEmptyAtclauseDescription]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\CrawlerPack.java:423: At-clause should have a non-empty description. [NonEmptyAtclauseDescription]

[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\XTrustProvider.java:46:1: Missing a Javadoc comment. [MissingJavadocType]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\XTrustProvider.java:53:5: Missing a Javadoc comment. [MissingJavadocMethod]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\XTrustProvider.java:68:5: Missing a Javadoc comment. [MissingJavadocMethod]
[WARN] \CrawlerPack\src\main\java\com\github\abola\crawler\XTrustProvider.java:78:5: Missing a Javadoc comment. [MissingJavadocType]
[WARN] \CrawlerPack\src\main\java\org\jsoup\parser\PrefixXmlTreeBuilder.java:28:1: Missing a Javadoc comment. [MissingJavadocType]
the above violations are all same type, mission the javadoc or part of it
reason to solve them: it will help others to understand your code more easier and it is really easy to fix

line109 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line62 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line72 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line89 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line104 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line35 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line141 PrefixXmlTreeBuilder.java Add the "@OverRide" annotation above this method signature
line114 PrefixXmlTreeBuilder.java Rename this method; there is a "private" method in the parent class with the same name.
reason to fix above violations: since this kind of violation may cause people confuse when use the function, fix them can make people understand your code more easier, and also they are easy to fix

line158 CrawlerPack.java Return an empty array instead of null.
line94 XTrustProvider.java Return an empty array instead of null.
reason to fix above violations: these do not cause fail,but when product the project in the future, this is easy to cause a NullPointerException, so if you have free time, change it to new collection() well be much better

line366 CrawlerPack.java This block of commented-out lines of code should be removed.
this is just a duplicate comment, you write a part of command twice, a little confuse people

line348 CrawlerPack.java Rename this constant name to match the regular expression '^[A-Z][A-Z0-9](_[A-Z0-9]+)$'.
to make the product of this project in the future more easier