update

# File lib/rubygems/user_interaction.rb, line 624
    def update(bytes)
      new_progress = if @units == 'B' then
                       bytes
                     else
                       ((bytes.to_f * 100) / total_bytes.to_f).ceil
                     end

      return if new_progress == @progress

      @progress = new_progress
      update_display
    end