title: How to pass self into a decorator?
body: <p>How do I pass <code>self.key</code> below into the decorator?</p>
  
  <pre><code>class CacheMix(object):
  
      def __init__(self, *args, **kwargs):
          super(CacheMix, self).__init__(*args, **kwargs)
  
      key_func = Constructor(
          memoize_for_request=True,
          params={'updated_at': self.key}
      )
  
      @cache_response(key_func=key_func)
      def list(self, *args, **kwargs):
          pass
  
  class ListView(CacheMix, generics.ListCreateAPIView):
      key = 'test_key'
  </code></pre>
  
  <p>I get the error:</p>
  
  <pre class="lang-none prettyprint-override"><code>'self' is not defined
  </code></pre>