code: def write(self, proto):
      
      # Write base class to proto.baseTM (BacktrackingTMProto)
      super(BacktrackingTMCPP, self).write(proto.baseTM)
      self.cells4.write(proto.cells4)
      proto.makeCells4Ephemeral = self.makeCells4Ephemeral
      proto.seed = self.seed
      proto.checkSynapseConsistency = self.checkSynapseConsistency
      proto.initArgs = json.dumps(self._initArgsDict)
docs: Populate serialization proto instance.
  
      :param proto: (BacktrackingTMCppProto) the proto instance to populate