@ SuppressWarnings ( "nls" ) private void checkNotNull ( Object sourceClass , Object eventSetName , Object alistenerType , Object listenerMethodName ) { if ( sourceClass == null ) { throw new NullPointerException ( Messages . getString ( "beans.0C" ) ) ; } if ( eventSetName == null ) { throw new NullPointerException ( Messages . getString ( "beans.53" ) ) ; } if ( alistenerType == null ) { throw new NullPointerException ( Messages . getString ( "beans.54" ) ) ; } if ( listenerMethodName == null ) { throw new NullPointerException ( Messages . getString ( "beans.52" ) ) ; } }
ensures that there is no nulls