code: protected function adjustLabelFor($options)
      {
          if (!isset($options['id'])) {
              return;
          }
          $this->_inputId = $options['id'];
          if (!isset($this->labelOptions['for'])) {
              $this->labelOptions['for'] = $options['id'];
          }
      }
docs: Adjusts the `for` attribute for the label based on the input options.
  @param array $options the input options.