is_followed_by_id() public method

如果源用户或目的用户不存在,将返回http的400错误
对应API:{@link http://open.weibo.com/wiki/2/friendships/show friendships/show}
public is_followed_by_id ( mixed $target_id, mixed $source_id = NULL ) : array
$target_id mixed 目标用户UID
$source_id mixed 源用户UID,可选,默认为当前的用户
return array
}
if (0 === count($followers_ids)) {
    $unpass_tasks = $do_tasks;
} else {
    $unpass_tasks = array_diff($do_tasks, $followers_ids['ids']);
}
if (0 != count($unpass_tasks)) {
    foreach ($unpass_tasks as $k => $v) {
        // $k -- user_id, $v -- uid
        $sql = "select nick_name from user where user_id = {$k} limit 1";
        $sql_res = $dbo->getRow($sql);
        echo 'user_id:' . $k . ';  weibo_mid: ' . $v . '; 用户名:' . $sql_res['nick_name'] . "\n";
    }
    // 对未通过draft1验证的用户进行精确验证
    foreach ($unpass_tasks as $k => $v) {
        $result = $c->is_followed_by_id($v, $task_uid);
        if_weiboapi_fail($result);
        if (!$result['target']['following']) {
            $failed[$k] = $v;
        }
    }
    echo "failed by draft2\n";
    echo "----------------------\n";
    if (0 === count($failed)) {
        echo "NONE\n";
    } else {
        foreach ($failed as $k => $v) {
            // $k -- user_id, $v -- mid
            $sql = "select nick_name from user where user_id = {$k} limit 1";
            $sql_res = $dbo->getRow($sql);
            echo 'user_id:' . $k . ';  sina_uid: ' . $v . '; 用户名:' . $sql_res['nick_name'] . "\n";