319    * Disables all rules.

   320    * @return null

   321    */

   322   

   323   public function disable_all_rules()

   324   {

   325     $this->rules = array();

   326     return null;

   327   }

   328   

   329   /**

   330    * Enables a rule

   331    * @param string rule

   332    * @return null

   333    */

   334    

   335   public function enable_rule($rule)

   336   {

   337     $this->rules[] = $rule;

   338     return null;

   339   }

   340   

   341   /**