public OkRequest<T> form(final Map.Entry<String, String> entry) {
        return form(entry, CHARSET_UTF8);
    }
public OkRequest < T > form ( final Map . Entry < String , String > entry ) { return form ( entry , CHARSET_UTF8 ) ; }
Write the key and value in the entry as form data to the request body
<p/>
The pair specified will be URL-encoded in UTF-8 and sent with the
'application/x-www-form-urlencoded' content-type

@param entry
@return this request