original_string: public static function get_instance_for_cache(\cache_definition $definition) {
          if (is_null(self::$instance)) {
              self::$instance = new time_last_message_between_users();
          }
          return self::$instance;
      }
code: public static function get_instance_for_cache(\cache_definition $definition) {
          if (is_null(self::$instance)) {
              self::$instance = new time_last_message_between_users();
          }
          return self::$instance;
      }
code_tokens: public static function get_instance_for_cache ( \ cache_definition $ definition ) { if ( is_null ( self :: $ instance ) ) { self :: $ instance = new time_last_message_between_users ( ) ; } return self :: $ instance ; }
docstring: Returns an instance of the data source class that the cache can use for loading data using the other methods
  specified by the cache_data_source interface.
  
  @param \cache_definition $definition
  @return object
docstring_tokens: Returns an instance of the data source class that the cache can use for loading data using the other methods specified by the cache_data_source interface .