# File lib/eymiha/util/envelope.rb, line 70
    def add(value)
      if value.kind_of? Envelope
        count = value.count
        if (count > 0)
          add value.high
          add value.low
          @count += (count-2)
        end
        self
      else
        begin
          @high = value if (@count == 0 || value > @high)
          @low = value if (@count == 0 || value < @low)
          @count += 1
          self
        rescue
          raise_no_compare value
        end
      end
    end