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

    B 󥳡ɤ줿 RFC2822 ʸɽ֤ޤ
    ɤ eolʸ󥳡ǥ󥰤 encoding Ȥޤ
     encoding  j Ƥޤ

