in lib/src/message.dart [223:231]
bool _sameEncoding(Map<String, List<String>?>? headers, Body body) {
if (body.encoding == null) return true;
var contentType = findHeader(headers, 'content-type');
if (contentType == null) return false;
var charset = MediaType.parse(contentType).parameters['charset'];
return Encoding.getByName(charset) == body.encoding;
}