add a class if the comment is a parent

// Create and array of all parent comments
		$parents = array();
		foreach ($comments as $cmnt) {
			$parents[] = $cmnt->comment_parent;
		}
		// If the comment ID is in the array of parent above add a class
		if ( in_array( $comment->comment_ID, $parents ) ){
			$c[] = 'threaded-comment';
		}