private static boolean checkOwnerOccurrences(final Project project, final Collection<PsiElement> occurrences, final boolean isClosure) {
    boolean result = true;
    final StringBuilder msg = new StringBuilder();
    msg.append(
      isClosure ? GroovyBundle.message("conversion.closure.not.allowed.in.non.groovy.files")
                : GroovyBundle.message("conversion.method.not.allowed.in.non.groovy.files")
    );
    for (PsiElement element : occurrences) {
      final PsiFile file = element.getContainingFile();
      if (!(file instanceof GroovyFileBase)) {
        result = false;
        msg.append("\n").append(file.getName());
      }
    }
    if (!result) {
      @NlsSafe String message = msg.toString();
      showErrorMessage(message, project);
      return false;
    }
    return true;
  }
private static boolean checkOwnerOccurrences(final Project project, final Collection<PsiElement> occurrences, final boolean isClosure)