public function start($metric, array $tags = array(), $sampleRate = AbstractMetric::DEFAULT_SAMPLE_RATE)
    {
        try {
            $this->timers[$metric] = $this->metricFactory->timer($metric, null, $tags, $sampleRate);
            $this->timers[$metric]->start();
        } catch (\Exception $exception) {
            $this->logException($exception);
        }

        return $this;
    }