def to_hash
      h = super
      h['timed_stats'] = @timed_stats.to_hash
      h['value_stats'] = @value_stats.to_hash( Stats::STATS - %w[ rate ] )
      h['rate'] = self.rate
      h['unit_count'] = self.unit_count
      return h
    end
def to_hash
      h = super
      h['timed_stats'] = @timed_stats.to_hash
      h['value_stats'] = @value_stats.to_hash( Stats::STATS - %w[ rate ] )
      h['rate'] = self.rate
      h['unit_count'] = self.unit_count
      return h
    end
:call-seq:
   metric.to_hash -> Hash

 Convert the metric to a hash