code: function validateProps(element, props) {
    // TODO (yungsters): Remove support for `selected` in <option>.
    {
      if (props.selected != null && !didWarnSelectedSetOnOption) {
        warning(false, 'Use the `defaultValue` or `value` props on <select> instead of ' + 'setting `selected` on <option>.');
        didWarnSelectedSetOnOption = true;
      }
    }
  }
docs: Implements an <option> host component that warns when `selected` is set.