code: def CallFlow(self,
                 flow_name=None,
                 next_state=None,
                 request_data=None,
                 client_id=None,
                 **kwargs):
      
      base_session_id = None
      if client_id:
        # The flow is stored in the hunt namespace,
        base_session_id = self.urn.Add(client_id.Basename())
  
      # Actually start the new flow.
      child_urn = self.runner.CallFlow(
          flow_name=flow_name,
          next_state=next_state,
          base_session_id=base_session_id,
          client_id=client_id,
          request_data=request_data,
          **kwargs)
  
      if client_id:
        # But we also create a symlink to it from the client's namespace.
        hunt_link_urn = client_id.Add("flows").Add("%s:hunt" %
                                                   (self.urn.Basename()))
  
        hunt_link = aff4.FACTORY.Create(
            hunt_link_urn, aff4.AFF4Symlink, token=self.token)
  
        hunt_link.Set(hunt_link.Schema.SYMLINK_TARGET(child_urn))
        hunt_link.Close()
  
      return child_urn
docs: Create a new child flow from a hunt.