title: How to re-rerun the dag which was already executed using TriggerDagrunoperator?
body: <p>I have a dag,where i'm using list of below operators</p>
  
  <ul>
  <li>TriggerDagrunoperator-to trigger another dag  </li>
  <li>ExternalTaskSensor-Get the status of triggered dag</li>
  </ul>
  
  <p>My use case:
  Say for instance, if entire flow completed successfully, and i found some issue with processing of data in between. I want to re-run the job for that particular execution date from point of issue. I cleared the downstream and it makes the job to re-run. But, TriggerDagrunoperator fails with below issue.</p>
  
  <p>airflow.exceptions.DagRunAlreadyExists: Run id triggered_ :  already exists for dag id</p>
  
  <p>I want to clear that and need to re-run the dag again for that particular execution date. Any better way to accomplish that?</p>