@Override
  public boolean isAcceptable(Object element, @Nullable PsiElement context) {
    // Do not suggest final/sealed library classes
    return !(element instanceof PsiClass) ||
           !(element instanceof PsiCompiledElement) ||
           !((PsiClass)element).hasModifierProperty(PsiModifier.FINAL) &&
           !((PsiClass)element).hasModifierProperty(PsiModifier.SEALED);
  }
@Override
  public boolean isAcceptable(Object element, @Nullable PsiElement context)