code: def update(self, friendly_name=values.unset,
                 assignment_callback_url=values.unset,
                 fallback_assignment_callback_url=values.unset,
                 configuration=values.unset, task_reservation_timeout=values.unset):
          
          return self._proxy.update(
              friendly_name=friendly_name,
              assignment_callback_url=assignment_callback_url,
              fallback_assignment_callback_url=fallback_assignment_callback_url,
              configuration=configuration,
              task_reservation_timeout=task_reservation_timeout,
          )
docs: Update the WorkflowInstance
  
          :param unicode friendly_name: A string representing a human readable name for this Workflow.
          :param unicode assignment_callback_url: A valid URL for the application that will process task assignment events.
          :param unicode fallback_assignment_callback_url: If the request to the AssignmentCallbackUrl fails, the assignment callback will be made to this URL.
          :param unicode configuration: JSON document configuring the rules for this Workflow.
          :param unicode task_reservation_timeout: An integer value controlling how long in seconds TaskRouter will wait for a confirmation response from your application after assigning a Task to a worker.
  
          :returns: Updated WorkflowInstance
          :rtype: twilio.rest.taskrouter.v1.workspace.workflow.WorkflowInstance