public JCDiagnostic warning(DiagnosticSource source,DiagnosticPosition pos,String key,Object... args){
  return create(WARNING,null,EnumSet.noneOf(DiagnosticFlag.class),source,pos,key,args);
}

public JCDiagnostic warning ( DiagnosticSource source , DiagnosticPosition pos , String key , Object ... args ) { return create ( WARNING , null , EnumSet . noneOf ( DiagnosticFlag . class ) , source , pos , key , args ) ; }
create a warning diagnostic .
