@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;
  }
  @NotNull
  private static PsiClass[] getSupersInner(@NotNull PsiClass psiClass) {
    PsiClassType[] extendsListTypes = psiClass.getExtendsListTypes();
    PsiClassType[] implementsListTypes = psiClass.getImplementsListTypes();

    if (psiClass.isInterface()) {
      return resolveClassReferenceList(
          extendsListTypes, psiClass.getManager(), psiClass.getResolveScope(), true);
    }

    if (psiClass instanceof PsiAnonymousClass) {
      PsiAnonymousClass psiAnonymousClass = (PsiAnonymousClass) psiClass;
      PsiClassType baseClassReference = psiAnonymousClass.getBaseClassType();
      PsiClass baseClass = baseClassReference.resolve();
      if (baseClass != null) {
        if (baseClass.isInterface()) {
          PsiClass objectClass =
              JavaPsiFacade.getInstance(psiClass.getProject())
                  .findClass(CommonClassNames.JAVA_LANG_OBJECT, psiClass.getResolveScope());
          return objectClass != null
              ? new PsiClass[] {objectClass, baseClass}
              : new PsiClass[] {baseClass};
        }
        return new PsiClass[] {baseClass};
      }

      PsiClass objectClass =
          JavaPsiFacade.getInstance(psiClass.getProject())
              .findClass(CommonClassNames.JAVA_LANG_OBJECT, psiClass.getResolveScope());
      return objectClass != null ? new PsiClass[] {objectClass} : PsiClass.EMPTY_ARRAY;
    }
    if (psiClass instanceof PsiTypeParameter) {
      if (extendsListTypes.length == 0) {
        final PsiClass objectClass =
            JavaPsiFacade.getInstance(psiClass.getProject())
                .findClass(CommonClassNames.JAVA_LANG_OBJECT, psiClass.getResolveScope());
        return objectClass != null ? new PsiClass[] {objectClass} : PsiClass.EMPTY_ARRAY;
      }
      return resolveClassReferenceList(
          extendsListTypes, psiClass.getManager(), psiClass.getResolveScope(), false);
    }

    PsiClass[] interfaces =
        resolveClassReferenceList(
            implementsListTypes, psiClass.getManager(), psiClass.getResolveScope(), false);

    PsiClass superClass = getSuperClass(psiClass);
    if (superClass == null) return interfaces;
    PsiClass[] types = new PsiClass[interfaces.length + 1];
    types[0] = superClass;
    System.arraycopy(interfaces, 0, types, 1, interfaces.length);

    return types;
  }
  @NotNull
  public static PsiClass[] getInterfaces(@NotNull PsiClass psiClass) {
    if (psiClass.isInterface()) {
      final PsiClassType[] extendsListTypes = psiClass.getExtendsListTypes();
      return resolveClassReferenceList(
          extendsListTypes, psiClass.getManager(), psiClass.getResolveScope(), false);
    }

    if (psiClass instanceof PsiAnonymousClass) {
      PsiClassType baseClassReference = ((PsiAnonymousClass) psiClass).getBaseClassType();
      PsiClass baseClass = baseClassReference.resolve();
      return baseClass != null && baseClass.isInterface()
          ? new PsiClass[] {baseClass}
          : PsiClass.EMPTY_ARRAY;
    }

    final PsiClassType[] implementsListTypes = psiClass.getImplementsListTypes();
    return resolveClassReferenceList(
        implementsListTypes, psiClass.getManager(), psiClass.getResolveScope(), false);
  }
  @NotNull
  public static PsiClassType[] getSuperTypes(@NotNull PsiClass psiClass) {
    if (psiClass instanceof PsiAnonymousClass) {
      PsiClassType baseClassType = ((PsiAnonymousClass) psiClass).getBaseClassType();
      PsiClass baseClass = baseClassType.resolve();
      if (baseClass == null || !baseClass.isInterface()) {
        return new PsiClassType[] {baseClassType};
      } else {
        PsiClassType objectType =
            PsiType.getJavaLangObject(psiClass.getManager(), psiClass.getResolveScope());
        return new PsiClassType[] {objectType, baseClassType};
      }
    }

    PsiClassType[] extendsTypes = psiClass.getExtendsListTypes();
    PsiClassType[] implementsTypes = psiClass.getImplementsListTypes();
    boolean hasExtends = extendsTypes.length != 0;
    int extendsListLength = extendsTypes.length + (hasExtends ? 0 : 1);
    PsiClassType[] result = new PsiClassType[extendsListLength + implementsTypes.length];

    System.arraycopy(extendsTypes, 0, result, 0, extendsTypes.length);
    if (!hasExtends) {
      if (CommonClassNames.JAVA_LANG_OBJECT.equals(psiClass.getQualifiedName())) {
        return PsiClassType.EMPTY_ARRAY;
      }
      PsiManager manager = psiClass.getManager();
      PsiClassType objectType = PsiType.getJavaLangObject(manager, psiClass.getResolveScope());
      result[0] = objectType;
    }
    System.arraycopy(implementsTypes, 0, result, extendsListLength, implementsTypes.length);
    for (int i = 0; i < result.length; i++) {
      PsiClassType type = result[i];
      result[i] = (PsiClassType) PsiUtil.captureToplevelWildcards(type, psiClass);
    }
    return result;
  }
  @Nullable
  private PsiType getNominalTypeInner(@Nullable PsiElement resolved) {
    if (resolved == null && !"class".equals(getReferenceName())) {
      resolved = resolve();
    }

    if (resolved instanceof PsiClass) {
      final PsiElementFactory factory = JavaPsiFacade.getInstance(getProject()).getElementFactory();
      if (PsiUtil.isInstanceThisRef(this)) {
        final PsiClassType categoryType = GdkMethodUtil.getCategoryType((PsiClass) resolved);
        if (categoryType != null) {
          return categoryType;
        } else {
          return factory.createType((PsiClass) resolved);
        }
      } else if (PsiUtil.isSuperReference(this)) {
        PsiClass contextClass = PsiUtil.getContextClass(this);
        if (GrTraitUtil.isTrait(contextClass)) {
          PsiClassType[] extendsTypes = contextClass.getExtendsListTypes();
          PsiClassType[] implementsTypes = contextClass.getImplementsListTypes();

          PsiClassType[] superTypes =
              ArrayUtil.mergeArrays(implementsTypes, extendsTypes, PsiClassType.ARRAY_FACTORY);

          return PsiIntersectionType.createIntersection(ArrayUtil.reverseArray(superTypes));
        }
        return factory.createType((PsiClass) resolved);
      }
      if (getParent() instanceof GrReferenceExpression) {
        return factory.createType((PsiClass) resolved);
      } else {
        return TypesUtil.createJavaLangClassType(
            factory.createType((PsiClass) resolved), getProject(), getResolveScope());
      }
    }

    if (resolved instanceof GrVariable) {
      return ((GrVariable) resolved).getDeclaredType();
    }

    if (resolved instanceof PsiVariable) {
      return ((PsiVariable) resolved).getType();
    }

    if (resolved instanceof PsiMethod) {
      PsiMethod method = (PsiMethod) resolved;
      if (PropertyUtil.isSimplePropertySetter(method)
          && !method.getName().equals(getReferenceName())) {
        return method.getParameterList().getParameters()[0].getType();
      }

      // 'class' property with explicit generic
      PsiClass containingClass = method.getContainingClass();
      if (containingClass != null
          && CommonClassNames.JAVA_LANG_OBJECT.equals(containingClass.getQualifiedName())
          && "getClass".equals(method.getName())) {
        return TypesUtil.createJavaLangClassType(
            PsiImplUtil.getQualifierType(this), getProject(), getResolveScope());
      }

      return PsiUtil.getSmartReturnType(method);
    }

    if (resolved == null) {
      final PsiType fromClassRef = getTypeFromClassRef(this);
      if (fromClassRef != null) {
        return fromClassRef;
      }

      final PsiType fromMapAccess = getTypeFromMapAccess(this);
      if (fromMapAccess != null) {
        return fromMapAccess;
      }

      final PsiType fromSpreadOperator = getTypeFromSpreadOperator(this);
      if (fromSpreadOperator != null) {
        return fromSpreadOperator;
      }
    }

    return null;
  }