code: def channels(self, use_cached=False, **params_to_override):
          
          return collections.OrderedDict({ 'default':self.__call__(**params_to_override) })
docs: Channels() adds a shared interface for single channel and
          multichannel structures.  It will always return an ordered
          dict: its first element is the single channel of the pattern
          (if single-channel) or the channel average (if multichannel);
          the successive elements are the individual channels' arrays
          (key: 0,1,..N-1).