code: def _meta(self, entity_id, includes, channel=None):
          '''Retrieve metadata about an entity in the charmstore.
  
          @param entity_id The ID either a reference or a string of the entity
                 to get.
          @param includes Which metadata fields to include in the response.
          @param channel Optional channel name, e.g. `stable`.
          '''
          queries = []
          if includes is not None:
              queries.extend([('include', include) for include in includes])
          if channel is not None:
              queries.append(('channel', channel))
          if len(queries):
              url = '{}/{}/meta/any?{}'.format(self.url, _get_path(entity_id),
                                               urlencode(queries))
          else:
              url = '{}/{}/meta/any'.format(self.url, _get_path(entity_id))
          data = self._get(url)
          return data.json(f _meta(self, entity_id, includes, channel=None):
          '''Retrieve metadata about an entity in the charmstore.
  
          @param entity_id The ID either a reference or a string of the entity
                 to get.
          @param includes Which metadata fields to include in the response.
          @param channel Optional channel name, e.g. `stable`.
          '''
          queries = []
          if includes is not None:
              queries.extend([('include', include) for include in includes])
          if channel is not None:
              queries.append(('channel', channel))
          if len(queries):
              url = '{}/{}/meta/any?{}'.format(self.url, _get_path(entity_id),
                                               urlencode(queries))
          else:
              url = '{}/{}/meta/any'.format(self.url, _get_path(entity_id))
          data = self._get(url)
          return data.json()
docs: Retrieve metadata about an entity in the charmstore.
  
          @param entity_id The ID either a reference or a string of the entity
                 to get.
          @param includes Which metadata fields to include in the response.
          @param channel Optional channel name, e.g. `stable`.