private function registerDirectives()
  {
    $this->register(Not::class);
    $this->register(EndEmpty::class);
    $this->register(EndIsset::class);
    $this->register(EndNot::class);
    $this->register(EndNull::class);

    return true;
  }
private function registerDirectives()
  {
    $this->register(Not::class);
    $this->register(EndEmpty::class);
    $this->register(EndIsset::class);
    $this->register(EndNot::class);
    $this->register(EndNull::class);

    return true;
  }
private function registerDirectives ( ) { $ this -> register ( Not :: class ) ; $ this -> register ( EndEmpty :: class ) ; $ this -> register ( EndIsset :: class ) ; $ this -> register ( EndNot :: class ) ; $ this -> register ( EndNull :: class ) ; return true ; }
Register custom directives

@return boolean
Register custom directives