@Override
 public boolean accepts(
     @NotNull PsiSwitchStatement psiSwitchStatement,
     ProcessingContext context) {
   final PsiExpression expression =
       psiSwitchStatement.getExpression();
   if (expression == null) return false;
   PsiClass aClass =
       PsiUtil.resolveClassInClassTypeOnly(expression.getType());
   return aClass != null && aClass.isEnum();
 }
  private static boolean superConstructorHasParameters(PsiMethod method) {
    final PsiClass psiClass = method.getContainingClass();
    if (psiClass == null) {
      return false;
    }

    final PsiClass superClass = psiClass.getSuperClass();
    if (superClass != null) {
      for (final PsiMethod psiMethod : superClass.getConstructors()) {
        final PsiResolveHelper resolveHelper =
            JavaPsiFacade.getInstance(method.getProject()).getResolveHelper();
        if (resolveHelper.isAccessible(psiMethod, method, null)
            && psiMethod.getParameterList().getParameters().length > 0) {
          return true;
        }
      }
    }
    return false;
  }
  private static void completeAnnotationAttributeName(
      CompletionResultSet result, PsiElement insertedElement, CompletionParameters parameters) {
    PsiNameValuePair pair = PsiTreeUtil.getParentOfType(insertedElement, PsiNameValuePair.class);
    PsiAnnotationParameterList parameterList = (PsiAnnotationParameterList) pair.getParent();
    PsiAnnotation anno = (PsiAnnotation) parameterList.getParent();
    boolean showClasses = psiElement().afterLeaf("(").accepts(insertedElement);
    PsiClass annoClass = null;
    final PsiJavaCodeReferenceElement referenceElement = anno.getNameReferenceElement();
    if (referenceElement != null) {
      final PsiElement element = referenceElement.resolve();
      if (element instanceof PsiClass) {
        annoClass = (PsiClass) element;
        if (annoClass.findMethodsByName("value", false).length == 0) {
          showClasses = false;
        }
      }
    }

    if (showClasses && insertedElement.getParent() instanceof PsiReferenceExpression) {
      final Set<LookupElement> set =
          JavaCompletionUtil.processJavaReference(
              insertedElement,
              (PsiJavaReference) insertedElement.getParent(),
              new ElementExtractorFilter(createAnnotationFilter(insertedElement)),
              JavaCompletionProcessor.Options.DEFAULT_OPTIONS,
              result.getPrefixMatcher(),
              parameters);
      for (final LookupElement element : set) {
        result.addElement(element);
      }
      addAllClasses(parameters, result, new InheritorsHolder(insertedElement, result));
    }

    if (annoClass != null) {
      final PsiNameValuePair[] existingPairs = parameterList.getAttributes();

      methods:
      for (PsiMethod method : annoClass.getMethods()) {
        if (!(method instanceof PsiAnnotationMethod)) continue;

        final String attrName = method.getName();
        for (PsiNameValuePair existingAttr : existingPairs) {
          if (PsiTreeUtil.isAncestor(existingAttr, insertedElement, false)) break;
          if (Comparing.equal(existingAttr.getName(), attrName)
              || PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME.equals(attrName)
                  && existingAttr.getName() == null) continue methods;
        }
        LookupElementBuilder element =
            LookupElementBuilder.createWithIcon(method)
                .withInsertHandler(
                    new InsertHandler<LookupElement>() {
                      @Override
                      public void handleInsert(InsertionContext context, LookupElement item) {
                        final Editor editor = context.getEditor();
                        TailType.EQ.processTail(editor, editor.getCaretModel().getOffset());
                        context.setAddCompletionChar(false);

                        context.commitDocument();
                        PsiAnnotationParameterList paramList =
                            PsiTreeUtil.findElementOfClassAtOffset(
                                context.getFile(),
                                context.getStartOffset(),
                                PsiAnnotationParameterList.class,
                                false);
                        if (paramList != null
                            && paramList.getAttributes().length > 0
                            && paramList.getAttributes()[0].getName() == null) {
                          int valueOffset =
                              paramList.getAttributes()[0].getTextRange().getStartOffset();
                          context
                              .getDocument()
                              .insertString(
                                  valueOffset, PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME);
                          TailType.EQ.processTail(
                              editor,
                              valueOffset + PsiAnnotation.DEFAULT_REFERENCED_METHOD_NAME.length());
                        }
                      }
                    });

        PsiAnnotationMemberValue defaultValue = ((PsiAnnotationMethod) method).getDefaultValue();
        if (defaultValue != null) {
          Object constant =
              JavaPsiFacade.getInstance(method.getProject())
                  .getConstantEvaluationHelper()
                  .computeConstantExpression(defaultValue);
          if (constant != null) {
            element =
                element.withTailText(
                    " default " + (constant instanceof String ? "\"" + constant + "\"" : constant),
                    true);
          }
        }

        result.addElement(element);
      }
    }
  }