question: private Method findAddRemoveListenerMethod ( Class < ? > sourceClass , String methodName ) throws IntrospectionException { try { return sourceClass . getMethod ( methodName , listenerType ) ; } catch ( NoSuchMethodException e ) { return findAddRemoveListnerMethodWithLessCheck ( sourceClass , methodName ) ; } catch ( Exception e ) { throw new IntrospectionException ( Messages . getString ( "beans.31" , methodName , listenerType . getName ( ) ) ) ; } }
target:  Searches for {add|remove}Listener methods in the event source. Parameter check is also performed.