How to exclude the child comments in get_comments() query?

How do I only get the first level of comments in get_comments() or WP_Comment_Query? I want to query the comments which have 'comment_parent' => 0, and exclude all the child comments.

    $args = array(
        'number'      => 10,
        'order'       => 'DESC',
        'status'      => 'approve',
    );

    $comments = get_comments( $args );