public static boolean isClassEquivalentTo(@NotNull PsiClass aClass, PsiElement another) {
    if (aClass == another) return true;
    if (!(another instanceof PsiClass)) return false;
    String name1 = aClass.getName();
    if (name1 == null) return false;
    if (!another.isValid()) return false;
    String name2 = ((PsiClass) another).getName();
    if (name2 == null) return false;
    if (name1.hashCode() != name2.hashCode()) return false;
    if (!name1.equals(name2)) return false;
    String qName1 = aClass.getQualifiedName();
    String qName2 = ((PsiClass) another).getQualifiedName();
    if (qName1 == null || qName2 == null) {
      //noinspection StringEquality
      if (qName1 != qName2) return false;

      if (aClass instanceof PsiTypeParameter && another instanceof PsiTypeParameter) {
        PsiTypeParameter p1 = (PsiTypeParameter) aClass;
        PsiTypeParameter p2 = (PsiTypeParameter) another;

        return p1.getIndex() == p2.getIndex()
            && aClass.getManager().areElementsEquivalent(p1.getOwner(), p2.getOwner());
      } else {
        return false;
      }
    }
    if (qName1.hashCode() != qName2.hashCode() || !qName1.equals(qName2)) {
      return false;
    }

    if (originalElement(aClass).equals(originalElement((PsiClass) another))) {
      return true;
    }

    final PsiFile file1 = aClass.getContainingFile().getOriginalFile();
    final PsiFile file2 = another.getContainingFile().getOriginalFile();

    // see com.intellij.openapi.vcs.changes.PsiChangeTracker
    // see com.intellij.psi.impl.PsiFileFactoryImpl#createFileFromText(CharSequence,PsiFile)
    final PsiFile original1 = file1.getUserData(PsiFileFactory.ORIGINAL_FILE);
    final PsiFile original2 = file2.getUserData(PsiFileFactory.ORIGINAL_FILE);
    if (original1 == original2 && original1 != null
        || original1 == file2
        || original2 == file1
        || file1 == file2) {
      return compareClassSeqNumber(aClass, (PsiClass) another);
    }

    final FileIndexFacade fileIndex =
        ServiceManager.getService(file1.getProject(), FileIndexFacade.class);
    final VirtualFile vfile1 = file1.getViewProvider().getVirtualFile();
    final VirtualFile vfile2 = file2.getViewProvider().getVirtualFile();
    boolean lib1 = fileIndex.isInLibraryClasses(vfile1);
    boolean lib2 = fileIndex.isInLibraryClasses(vfile2);

    return (fileIndex.isInSource(vfile1) || lib1) && (fileIndex.isInSource(vfile2) || lib2);
  }
  @NotNull
  public static SearchScope getClassUseScope(@NotNull PsiClass aClass) {
    if (aClass instanceof PsiAnonymousClass) {
      return new LocalSearchScope(aClass);
    }
    final GlobalSearchScope maximalUseScope = ResolveScopeManager.getElementUseScope(aClass);
    PsiFile file = aClass.getContainingFile();
    if (PsiImplUtil.isInServerPage(file)) return maximalUseScope;
    final PsiClass containingClass = aClass.getContainingClass();
    if (aClass.hasModifierProperty(PsiModifier.PUBLIC)
        || aClass.hasModifierProperty(PsiModifier.PROTECTED)) {
      return containingClass == null ? maximalUseScope : containingClass.getUseScope();
    } else if (aClass.hasModifierProperty(PsiModifier.PRIVATE)
        || aClass instanceof PsiTypeParameter) {
      PsiClass topClass = PsiUtil.getTopLevelClass(aClass);
      return new LocalSearchScope(topClass == null ? aClass.getContainingFile() : topClass);
    } else {
      PsiPackage aPackage = null;
      if (file instanceof PsiJavaFile) {
        aPackage =
            JavaPsiFacade.getInstance(aClass.getProject())
                .findPackage(((PsiJavaFile) file).getPackageName());
      }

      if (aPackage == null) {
        PsiDirectory dir = file.getContainingDirectory();
        if (dir != null) {
          aPackage = JavaDirectoryService.getInstance().getPackage(dir);
        }
      }

      if (aPackage != null) {
        SearchScope scope = PackageScope.packageScope(aPackage, false);
        scope = scope.intersectWith(maximalUseScope);
        return scope;
      }

      return new LocalSearchScope(file);
    }
  }