# File lib/ruport/data/grouping.rb, line 200
    def each 
      if @order.respond_to?(:call) 
        @data.sort_by { |n,g| @order[g] }.each { |n,g| yield(n,g) }
      elsif @order == :name
        @data.sort_by { |n,g| n }.each { |name,group| yield(name,group) } 
      else
        @data.each { |name,group| yield(name,group) }
      end
    end