code: func (e *engineImpl) AbortInvocation(c context.Context, job *Job, invID int64) error {
  	if err := job.CheckRole(c, acl.Owner); err != nil {
  		return err
  	}
  	return e.abortInvocation(c, job.JobID, invID)
  }
docs: // AbortInvocation forcefully moves the invocation to a failed state.
  //
  // Part of the public interface, checks ACLs.