function __construct()
 {
     self::$instance = $this;
     add_filter('omnisearch_results', array($this, 'search'), 12, 2);
     // Push 'post_type_obj' to accepted fields for WP_List_Table (since WP 4.2)
     global $wp_version;
     if (version_compare($wp_version, '4.2-z', '>=') && $this->compat_fields && is_array($this->compat_fields)) {
         array_push($this->compat_fields, 'post_type_obj');
     }
 }
 function __construct()
 {
     self::$instance = $this;
     add_filter('omnisearch_results', array($this, 'search'), 12, 2);
 }