/**
  * Return the single class instance
  *
  * @return object
  * @since 2.0.0
  */
 public static function instance()
 {
     if (is_null(self::$_instance)) {
         self::$_instance = new self();
     }
     return self::$_instance;
 }
 /**
  * Load compatibility code for previous WordPress versions
  *
  * @uses get_bloginfo()
  * @uses plugin_dir_path()
  *
  * @return void
  * @since 2.0.0
  */
 public function load_wordpress()
 {
     if (version_compare(get_bloginfo('version'), '3.9', '<')) {
         include_once plugin_dir_path(dirname(__FILE__)) . '/includes/class-compatibility-wordpress.php';
         self::$wordpress = Black_Studio_TinyMCE_Compatibility_Wordpress::instance();
     }
 }