java.lang.NullPointerException at com.javarush.task.task07.task0726.Solution.main(Solution.java:20) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at com.javarush.task.common.model.execution.ExecuteService.callMainMethod(ExecuteService.java:78) at com.javarush.task.common.model.execution.ExecuteService.execute(ExecuteService.java:102) at com.javarush.task.app.execution.ExecutionService.execute(ExecutionService.java:110) at com.javarush.task.app.execution.ExecutionService.main(ExecutionService.java:254) at com.javarush.task.app.MainApplication.main(MainApplication.java:49) a esli zakommentirovat` proverku "isEmpty", to vivodit: com/javarush/task/task07/task0726/Solution.java:31: error: unreachable statement printList(); ^