@Override
  public @NotNull IntentionPreviewInfo generatePreview(@NotNull Project project, @NotNull ProblemDescriptor previewDescriptor) {
    final PsiElement element = previewDescriptor.getPsiElement();
    PsiClass psiClass = PsiTreeUtil.getParentOfType(element, PsiClass.class);
    if (psiClass == null) return IntentionPreviewInfo.EMPTY;
    String textBefore = psiClass.getText();
    psiClass.setName("NewCustomName");
    String textAfter = psiClass.getText();
    return new IntentionPreviewInfo.CustomDiff(GroovyFileType.GROOVY_FILE_TYPE, textBefore, textAfter);
  }
@Override
  public @NotNull IntentionPreviewInfo generatePreview(@NotNull Project project, @NotNull ProblemDescriptor previewDescriptor)