code: def bits(self):
          
          try:
              return self._bits
          except AttributeError:
              if self.dtype.name.startswith(('uint', 'int')):
                  nbits = self.itemsize * 8
                  self.bits = Bits(['Bit %d' % b for b in range(nbits)],
                                   channel=self.channel, epoch=self.epoch)
                  return self.bits
              elif hasattr(self.channel, 'bits'):
                  self.bits = self.channel.bits
                  return self.bits
              return None
docs: list of `Bits` for this `StateVector`
  
          :type: `Bits`