@Nullable
  public static PsiClass getSuperClass(@NotNull PsiClass psiClass) {
    PsiManager manager = psiClass.getManager();
    GlobalSearchScope resolveScope = psiClass.getResolveScope();

    final JavaPsiFacade facade = JavaPsiFacade.getInstance(manager.getProject());
    if (psiClass.isInterface()) {
      return facade.findClass(CommonClassNames.JAVA_LANG_OBJECT, resolveScope);
    }
    if (psiClass.isEnum()) {
      return facade.findClass(CommonClassNames.JAVA_LANG_ENUM, resolveScope);
    }

    if (psiClass instanceof PsiAnonymousClass) {
      PsiClassType baseClassReference = ((PsiAnonymousClass) psiClass).getBaseClassType();
      PsiClass baseClass = baseClassReference.resolve();
      if (baseClass == null || baseClass.isInterface())
        return facade.findClass(CommonClassNames.JAVA_LANG_OBJECT, resolveScope);
      return baseClass;
    }

    if (CommonClassNames.JAVA_LANG_OBJECT.equals(psiClass.getQualifiedName())) return null;

    final PsiClassType[] referenceElements = psiClass.getExtendsListTypes();

    if (referenceElements.length == 0)
      return facade.findClass(CommonClassNames.JAVA_LANG_OBJECT, resolveScope);

    PsiClass psiResoved = referenceElements[0].resolve();
    return psiResoved == null
        ? facade.findClass(CommonClassNames.JAVA_LANG_OBJECT, resolveScope)
        : psiResoved;
  }