: encoded( eol = "\n", encoding = 'j' ) -> String
    eol: String
    encoding: String

    ᡼ RFC2822 ˥󥳡ɤʸѴޤ
    κݡإåιɤ eol ˡإåΥ󥳡
    ܸʸʸɤ encoding Ѵޤ
     encoding  "j" (JIS) ưޤ

    С 0.9  #to_s  #decoded ̾ˤʤäΤǡ
    ᥽åɤȤϰ㤦Ϥ餭򤷤ޤ

