function makeRequestTask(url, responseType) {
    var task = new Task();
    vendor.request.get({
        url: url,
        responseType: responseType,
        onload: function(res) {
            task.resolve(res);
        },
        onerror: function(error) {
            task.reject(error);
        }
    });
    return task;
}
If task finished, either successed or failed
@return {boolean}