Backend\Modules\Analytics\Form\DateRangeType::parse PHP Method

    public function parse(TwigTemplate $template)
    {
        $this->form->parse($template);
        $template->assign('startTimestamp', $this->dateRange->getStartDate());
        $template->assign('endTimestamp', $this->dateRange->getEndDate());
    }

 /**
  * The form will update the date range filter if needed
  */
 private function handleDateRangeForm()
 {
     $dateRangeForm = new DateRangeType('date_range', $this->dateRange);
     if ($dateRangeForm->handle()) {
         $this->dateRange = $dateRangeForm->getDateRange();
     }
     $dateRangeForm->parse($this->tpl);
 }