code: def to_dict(self):
          
          return {
              "gates": [km.to_dict() for km in self.gates],
              "assignment_probs": {str(qid): a.tolist() for qid, a in self.assignment_probs.items()},
          }
docs: Create a JSON serializable representation of the noise model.
  
          For example::
  
              {
                  "gates": [
                      # list of embedded dictionary representations of KrausModels here [...]
                  ]
                  "assignment_probs": {
                      "0": [[.8, .1],
                            [.2, .9]],
                      "1": [[.9, .4],
                            [.1, .6]],
                  }
              }
  
          :return: A dictionary representation of self.
          :rtype: Dict[str,Any]