def counter(self, key):
        if key not in self._counters:
            self._counters[key] = Counter()
        return self._counters[key]
Gets a counter based on a key, creates a new one if it does not exist.
dataset/ETHPy150Open cloudera/hue/desktop/core/ext-py/pyformance-0.3.2/pyformance/registry.py/MetricsRegistry.counter