code: private boolean aggregateExistsForCurrentMinute(final MetricIdentity identity) {
  		Preconditions.checkNotNull(identity);
  		
  		if (aggregates.containsKey(identity)) {			
  			if (aggregates.get(identity).containsKey(currentMinute)) {
  				return true;
  			}
  		}
  		
  		return false;
  	}
docs: Determines if the specified aggregate metric exists for the current minute
  @param identity The metric identity
  @return True if the metric exists, false otherwise