Nette\Forms\Rendering\DefaultFormRenderer::renderLabel PHP Method

    public function renderLabel(Nette\Forms\IControl $control)
    {
        $suffix = $this->getValue('label suffix') . ($control->isRequired() ? $this->getValue('label requiredsuffix') : '');
        $label = $control->getLabel();
        if ($label instanceof Html) {
            $label->addHtml($suffix);
            if ($control->isRequired()) {
                $label->class($this->getValue('control .required'), TRUE);
            }
        } elseif ($label != NULL) {
            // @intentionally ==
            $label .= $suffix;
        }
        return $this->getWrapper('label container')->setHtml($label);
    }

 public function renderLabel(Nette\Forms\IControl $control)
 {
     $this->controlsInit();
     return parent::renderLabel($control);
 }