/**
  * Return an instance of this class.
  *
  * @since     1.0.0
  *
  * @return    object    A single instance of this class.
  */
 public static function get_instance()
 {
     // If the single instance hasn't been set, set it now.
     if (null == self::$instance) {
         self::$instance = new self();
     }
     return self::$instance;
 }
 /**
  * Initialize the plugin by loading admin scripts & styles and adding a
  * settings page and menu.
  *
  * @since     1.0.0
  */
 private function __construct()
 {
     /*
      * Call $plugin_slug from public plugin class.
      */
     $plugin = Pods_Export_Code::get_instance();
     $this->plugin_slug = $plugin->get_plugin_slug();
     // Load admin style sheet and JavaScript.
     add_action('admin_enqueue_scripts', array($this, 'enqueue_admin_styles'));
     add_action('admin_enqueue_scripts', array($this, 'enqueue_admin_scripts'));
     // Hook into the pods admin menu
     add_filter('pods_admin_menu', array($this, 'add_plugin_admin_menu'));
     // Ajax handler
     add_action('wp_ajax_pods_export_code', array($this, 'pods_export_code'));
 }