# File lib/histogram.rb, line 35
  def add(key,count=1)
    if key.kind_of? Array
      key.each { |member|
        if member.kind_of? Array
          if member.size == 1
            add(member[0])
          elsif (member.size == 2) && (member[1].kind_of? Fixnum)
            add(member[0],member[1])
          else
            raise HistogramException, "add cannot interpret Array to add"
          end
        else
          add member
        end
      }
    elsif key.kind_of? Histogram
      key.each_pair { |k,v| add(k,v) }
    else
      self[key] = ((value = self[key]) == nil) ? count : value+count
    end
    self
  end