public function set_header($header, $value)
 {
     parent::set_header($header, $value);
     if ('Plural-Forms' == $header) {
         $this->_gettext_select_plural_form = $this->_make_gettext_select_plural_form($value);
     }
 }
 function set_header($header, $value)
 {
     parent::set_header($header, $value);
     if ('Plural-Forms' == $header) {
         list($nplurals, $expression) = $this->nplurals_and_expression_from_header($this->get_header('Plural-Forms'));
         $this->_nplurals = $nplurals;
         $this->_gettext_select_plural_form = $this->make_plural_form_function($nplurals, $expression);
     }
 }