我进行wp\\u查询，以控制注释计数和元键值。所以，我这样编码。但它不起作用。当我使用comment\\u cout only或meta\\u query only时，效果很好。当我一起使用时，它不能正常工作。我能得到一些帮助吗？非常感谢。

<?php
$arg = array(
    \'post_type\' => \'race\',
    \'posts_per_page\' => 5,
    \'comment_count\' => array(
        array(
            \'value\' => 10,
            \'compare\' => \'>=\',
        ),
    ),
    \'meta_query\' => array(
        // \'relation\' => \'AND\',
        array(
            \'key\'     => \'race_date\',
            \'value\'   => $today, //this is get by php time() function. ex) 2018-12-10
            \'compare\' => \'>=\',
        ),
    ),
    \'orderby\' => array(
        \'comment_count\' => \'DESC\',                           
    ),
);

$query = new WP_Query( $arg );
if ( $query->have_posts() ) {
    while ( $query->have_posts() ) {
        $query->the_post();
        $postid = get_the_ID();

        the_title();
        echo \'<br />\';
    }
    wp_reset_postdata();
}
?>