>> ERROR at line 37: "@abstract" annotation can only be used once per class.
>> ERROR at line 28: "@abstract" annotation can only be used once per function.
>> ERROR at line 35: "@abstract" annotation cannot be applied to static functions.
>> ERROR at line 11: Class "Test1" is not abstract but contains abstract methods. Mark the class as "@abstract" or remove "@abstract" from all methods in this class.
>> ERROR at line 14: Class "Test2" must implement "AbstractClass.some_func()" and other inherited abstract methods or be marked as "@abstract".
>> ERROR at line 17: Class "Test3" must implement "AbstractClassAgain.some_func()" and other inherited abstract methods or be marked as "@abstract".