title: Python 2.7 Combine abc.abstractmethod and classmethod
body: <p>How do I create a decorator for an abstract class method in Python 2.7?  </p>
  
  <p>Yes, this is similar to <a href="https://stackoverflow.com/questions/4474395/staticmethod-and-abc-abstractmethod-will-it-blend">this question</a>, except I would like to combine <code>abc.abstractmethod</code> and <code>classmethod</code>, instead of <code>staticmethod</code>.  Also, it looks like <code>abc.abstractclassmethod</code> was <a href="http://bugs.python.org/issue5867" rel="noreferrer">added in Python 3 (I think?)</a>, but I'm using Google App Engine, so I'm currently limited to Python 2.7</p>
  
  <p>Thanks in advance.</p>