--- URI::MailTo.build(ary)
--- URI::MailTo.build(hash)

    Ϳ줿 URI Ǥ URI::MailTo ֥Ȥޤ
    Ǥϡ
      [to, headers]
    󤫥ϥåͿޤheaders ϡʲΤ褦ʸ
    Ϳޤ

      "subject=subscribe&cc=addr"

      [["subject", "subscribe"], ["cc", "addr"]]

