code: public function setDate($date, $selector)
      {
          (new DatePicker($this, $selector, $date))->isDateAvailable()->setDate()->isDateSelected();
      }
docs: @param string $date
  @param string $selector
  
  @Then /^(?:|I )choose "([^"]*)" in "([^"]*)" datepicker$/
  @Then /^(?:|I )set the "([^"]*)" for "([^"]*)" datepicker$/