def _evaluate_trigger_rule(
            self,
            ti,
            successes,
            skipped,
            failed,
            upstream_failed,
            done,
            flag_upstream_failed,
            session):
        """
        
        """

        TR = airflow.utils.trigger_rule.TriggerRule

        task = ti.task
        upstream = len(task.upstream_task_ids)
        tr = task.trigger_rule
        upstream_done = done >= upstream
        upstream_tasks_state = {
            "total": upstream, "successes": successes, "skipped": skipped,
            "failed": failed, "upstream_failed": upstream_failed, "done": done
        }
        # TODO(aoen): Ideally each individual trigger rules would be its own class, but
        # this isn't very feasible at the moment since the database queries need to be
        # bundled together for efficiency.
        # handling instant state assignment based on trigger rules
        if flag_upstream_failed:
            if tr == TR.ALL_SUCCESS:
                if upstream_failed or failed:
                    ti.set_state(State.UPSTREAM_FAILED, session)
                elif skipped:
                    ti.set_state(State.SKIPPED, session)
            elif tr == TR.ALL_FAILED:
                if successes or skipped:
                    ti.set_state(State.SKIPPED, session)
            elif tr == TR.ONE_SUCCESS:
                if upstream_done and not successes:
                    ti.set_state(State.SKIPPED, session)
            elif tr == TR.ONE_FAILED:
                if upstream_done and not (failed or upstream_failed):
                    ti.set_state(State.SKIPPED, session)
            elif tr == TR.NONE_FAILED:
                if upstream_failed or failed:
                    ti.set_state(State.UPSTREAM_FAILED, session)
                elif skipped == upstream:
                    ti.set_state(State.SKIPPED, session)
            elif tr == TR.NONE_SKIPPED:
                if skipped:
                    ti.set_state(State.SKIPPED, session)

        if tr == TR.ONE_SUCCESS:
            if successes <= 0:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires one upstream "
                    "task success, but none were found. "
                    "upstream_tasks_state={1}, upstream_task_ids={2}"
                    .format(tr, upstream_tasks_state, task.upstream_task_ids))
        elif tr == TR.ONE_FAILED:
            if not failed and not upstream_failed:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires one upstream "
                    "task failure, but none were found. "
                    "upstream_tasks_state={1}, upstream_task_ids={2}"
                    .format(tr, upstream_tasks_state, task.upstream_task_ids))
        elif tr == TR.ALL_SUCCESS:
            num_failures = upstream - successes
            if num_failures > 0:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires all upstream "
                    "tasks to have succeeded, but found {1} non-success(es). "
                    "upstream_tasks_state={2}, upstream_task_ids={3}"
                    .format(tr, num_failures, upstream_tasks_state,
                            task.upstream_task_ids))
        elif tr == TR.ALL_FAILED:
            num_successes = upstream - failed - upstream_failed
            if num_successes > 0:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires all upstream "
                    "tasks to have failed, but found {1} non-failure(s). "
                    "upstream_tasks_state={2}, upstream_task_ids={3}"
                    .format(tr, num_successes, upstream_tasks_state,
                            task.upstream_task_ids))
        elif tr == TR.ALL_DONE:
            if not upstream_done:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires all upstream "
                    "tasks to have completed, but found {1} task(s) that "
                    "weren't done. upstream_tasks_state={2}, "
                    "upstream_task_ids={3}"
                    .format(tr, upstream_done, upstream_tasks_state,
                            task.upstream_task_ids))
        elif tr == TR.NONE_FAILED:
            num_failures = upstream - successes - skipped
            if num_failures > 0:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires all upstream "
                    "tasks to have succeeded or been skipped, but found {1} non-success(es). "
                    "upstream_tasks_state={2}, upstream_task_ids={3}"
                    .format(tr, num_failures, upstream_tasks_state,
                            task.upstream_task_ids))
        elif tr == TR.NONE_SKIPPED:
            if skipped > 0:
                yield self._failing_status(
                    reason="Task's trigger rule '{0}' requires all upstream "
                    "tasks to not have been skipped, but found {1} task(s) skipped. "
                    "upstream_tasks_state={2}, upstream_task_ids={3}"
                    .format(tr, skipped, upstream_tasks_state,
                            task.upstream_task_ids))
        else:
            yield self._failing_status(
                reason="No strategy to evaluate trigger rule '{0}'.".format(tr))