@Nullable public static String openDialog(Module module,String title,boolean includeAll,@Nullable Condition<PsiClass> filter,@NotNull String... classes){
  final Project project=module.getProject();
  final DumbService dumbService=DumbService.getInstance(project);
  if (dumbService.isDumb()) {
    dumbService.showDumbModeNotification(String.format("%1$s are not available while indices are updating.",title));
    return null;
  }
  final ChooseClassDialog dialog=new ChooseClassDialog(module,title,includeAll,filter,classes);
  return dialog.showAndGet() ? dialog.getClassName() : null;
}

@ Nullable public static String openDialog ( Module module , String title , boolean includeAll , @ Nullable Condition < PsiClass > filter , @ NotNull String ... classes ) { final Project project = module . getProject ( ) ; final DumbService dumbService = DumbService . getInstance ( project ) ; if ( dumbService . isDumb ( ) ) { dumbService . showDumbModeNotification ( String . format ( "%1$s are not available while indices are updating." , title ) ) ; return null ; } final ChooseClassDialog dialog = new ChooseClassDialog ( module , title , includeAll , filter , classes ) ; return dialog . showAndGet ( ) ? dialog . getClassName ( ) : null ; }
open a dialog if indices are available , otherwise show an error message .
