code: def set_state_from_file(self, filename):
          
          with self.io(filename, 'r') as fp:
              rstate = fp.read_random_state()
          # set the numpy random state
          numpy.random.set_state(rstate)
          # set emcee's generator to the same state
          self._sampler.random_state = rstate
docs: Sets the state of the sampler back to the instance saved in a file.