/**
  * initialize demo instance
  */
 private static function init()
 {
     if (empty(self::$instance)) {
         self::$instance = new self();
     }
     return self::$instance;
 }
 /**
  * @param $command
  * @param $args
  */
 public function install_sample_data_branch($command, $args)
 {
     //$demo = $command->get_segment_data('demo');
     $page = $command->get_segment_data('page');
     $configuration = $this->theme_config->item('configuration');
     if (empty($configuration['sample_data'])) {
         $configuration['sample_data'] = $command->get_segment_data('sample_data');
     }
     if (!empty($configuration['sample_data'])) {
         $demo = HW_Sample_Data::get_demo($configuration['sample_data']);
         //$this->theme_config->import($demo->get_demo_config_file());#do not need
         if ($demo) {
             $demo->set_active();
             $demo->install($page);
             $this->command_log('Install sample data for "' . $demo->info('title') . '".');
             return array('posts_count' => count($demo->importer->get_import_results('posts')) + 2);
         }
     }
 }