Symfony\Component\Form\Field::setLocale PHP Method

    public function setLocale($locale)
    {
        $this->locale = $locale;

        if ($this->valueTransformer !== null && $this->valueTransformer instanceof Localizable) {
            $this->valueTransformer->setLocale($locale);
        }
    }

 /**
  * Sets the locale of this field.
  *
  * @see Localizable
  */
 public function setLocale($locale)
 {
     parent::setLocale($locale);
     foreach ($this->fields as $field) {
         $field->setLocale($locale);
     }
 }