def to_hash
      h = super
      (Stats::STATS - %w[ rate ]).each do |s|
        h[s] = self.send( s ) 
      end
      return h
    end
def to_hash
      h = super
      (Stats::STATS - %w[ rate ]).each do |s|
        h[s] = self.send( s ) 
      end
      return h
    end
:call-seq:
   metric.to_hash -> Hash

 Convert the metric to a hash