def set_response_content_type(self, content_type_default,
                                  content_type_preferred=None):
        content_type = content_type_preferred
        if((not content_type) or (content_type.find("*") >= 0)):
            content_type = self.request.accept.best_matches()[0]
            if((not content_type) or (content_type.find("*") >= 0)):
                content_type = content_type_default
        self.response.headers[CONTENT_TYPE_HEADER] = content_type
        self.response.disp_out_type_ = content_type
Sets the response content-type header based on the request and the
dataset/ETHPy150Open jahlborn/appengine-rest-server/src/main/python/rest/__init__.py/Dispatcher.set_response_content_type