@Override
  public void incCounters(String key, long delta) {
    MutableFastCounter counter = metricsRegistry.getCounter(key, 0L);
    counter.incr(delta);

  }
Increment a named counter by some value.
@param key   the name of the counter
@param delta the ammount to increment
hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/metrics/BaseSourceImpl.java