Shortcut method for easy legacy cron jobs support.

def InitFromApiFlow(self, f, cron_job_id=None):
    """Shortcut method for easy legacy cron jobs support."""
    if f.flow_id:
      self.run_id = f.flow_id
    elif f.urn:
      self.run_id = f.urn.Basename()
    self.started_at = f.started_at
    self.cron_job_id = cron_job_id

    flow_state_enum = api_plugins_flow.ApiFlow.State
    cron_enum = rdf_cronjobs.CronJobRun.CronJobRunStatus
    errors_map = {
        flow_state_enum.RUNNING: cron_enum.RUNNING,
        flow_state_enum.TERMINATED: cron_enum.FINISHED,
        flow_state_enum.ERROR: cron_enum.ERROR,
        flow_state_enum.CLIENT_CRASHED: cron_enum.ERROR
    }
    self.status = errors_map[f.state]

    if f.state != f.State.RUNNING:
      self.finished_at = f.last_active_at

    if f.context.kill_timestamp:
      self.status = self.Status.LIFETIME_EXCEEDED

    if f.context.HasField("status"):
      self.log_message = f.context.status

    if f.context.HasField("backtrace"):
      self.backtrace = f.context.backtrace

    return self