code: def boolean(self):
          
          try:
              return self._boolean
          except AttributeError:
              nbits = len(self.bits)
              boolean = numpy.zeros((self.size, nbits), dtype=bool)
              for i, sample in enumerate(self.value):
                  boolean[i, :] = [int(sample) >> j & 1 for j in range(nbits)]
              self._boolean = Array2D(boolean, name=self.name,
                                      x0=self.x0, dx=self.dx, y0=0, dy=1)
              return self.boolean
docs: A mapping of this `StateVector` to a 2-D array containing all
          binary bits as booleans, for each time point.