Caused by: com.puppycrawl.tools.checkstyle.api.CheckstyleException: Exception was thrown while processing /home/r/repo/eo-parser/src/main/java/org/eolang/parser/CheckPack.java
at com.puppycrawl.tools.checkstyle.Checker.processFiles (Checker.java:302)
at com.puppycrawl.tools.checkstyle.Checker.process (Checker.java:221)
at com.qulice.checkstyle.CheckstyleValidator.validate (CheckstyleValidator.java:111)
at com.qulice.maven.CheckMojo$ValidatorCallable.call (CheckMojo.java:237)
at com.qulice.maven.CheckMojo$ValidatorCallable.call (CheckMojo.java:205)
at java.util.concurrent.FutureTask.run (FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1128)
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:628)
at java.lang.Thread.run (Thread.java:829)
Caused by: java.lang.NullPointerException
at com.qulice.checkstyle.DiamondOperatorCheck.isDiamondOperatorUsed (DiamondOperatorCheck.java:143)
at com.qulice.checkstyle.DiamondOperatorCheck.visitToken (DiamondOperatorCheck.java:110)
at com.puppycrawl.tools.checkstyle.TreeWalker.notifyVisit (TreeWalker.java:335)
at com.puppycrawl.tools.checkstyle.TreeWalker.processIter (TreeWalker.java:406)
at com.puppycrawl.tools.checkstyle.TreeWalker.walk (TreeWalker.java:273)
at com.puppycrawl.tools.checkstyle.TreeWalker.processFiltered (TreeWalker.java:154)
at com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck.process (AbstractFileSetCheck.java:87)
at com.puppycrawl.tools.checkstyle.Checker.processFile (Checker.java:328)
at com.puppycrawl.tools.checkstyle.Checker.processFiles (Checker.java:289)
at com.puppycrawl.tools.checkstyle.Checker.process (Checker.java:221)
at com.qulice.checkstyle.CheckstyleValidator.validate (CheckstyleValidator.java:111)
at com.qulice.maven.CheckMojo$ValidatorCallable.call (CheckMojo.java:237)
at com.qulice.maven.CheckMojo$ValidatorCallable.call (CheckMojo.java:205)
at java.util.concurrent.FutureTask.run (FutureTask.java:264)
at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java:1128)
at java.util.concurrent.ThreadPoolExecutor$Worker.run (ThreadPoolExecutor.java:628)
at java.lang.Thread.run (Thread.java:829)