# File lib/dnstraverse/referral.rb, line 227
    def stats_calculate_children(stats, children, weight)
      percent = (1.0 / children.length) * weight
      for child in children do
        child.stats.each_pair do |key, data|
          if not stats[key] then
            # just copy the child's statistics for this key
            stats[key] = data.dup
            stats[key][:prob]*= percent
          else
            stats[key][:prob]+= data[:prob] * percent
          end
        end
      end
    end