package contents type Option interface { KeyValue() [2]string } type CharSet string const ( Utf8 CharSet = "utf-8" ) func (cs CharSet) KeyValue() [2]string { return [2]string{ "charset", string(cs), } } type Type string const ( // Using the UTF-8 by default. Unknown Type = "application/octet-stream" Binary Plain= "text/plain" Css= "text/css" Html= "text/html" Json= "application/json" UrlEncoded= "application/x-www-form-urlencoded" )