'Send metrics to the app\'s `trace_logger` if set and
send to `log.debug` if this controller if `self.debugging`.
Precondition: metrics are parsed and in proper format.'

def _send_metrics(self, trans, metrics):

    if trans.app.trace_logger:
        for (label, time, kwargs) in metrics:
            trans.app.trace_logger.log(label, event_time=int(time), **kwargs)
    elif self.debugging:
        for (label, time, kwargs) in metrics:
            log.debug('%s    %s    %s', label, time, kwargs)
