# File lib/cheat.rb, line 84
  def diff_sheets(sheet, version)
    return unless version =~ /^(\d+)(:(\d+))?$/
    old_version, new_version = $1, $3

    uri = "http://#{cheat_uri}/d/#{sheet}/#{old_version}"
    uri += "/#{new_version}" if new_version

    fetch_sheet(uri, false)
  end