在TRestClient Delphi XE5中支持UTF-8编码字符串

I want to send tweets using the new TRest components in Delphi XE5. I am looking for a way to UTF8 encode my tweet which contains IS0-8859-1 characters. The code below works, but involves codepage conversion etc. Is the a better way? Anyone?I want to send tweets using the new TRest compo