✅ The input domain seems correct to me, since it should be a string or null and alien values should be reported.

Some context:

...
  public function getMenuItemProperty($key, $default = null) {
    return idx($this->menuItemProperties, $key, $default);
  }
...

✅ The input domain seems correct to me, since it should be a string or null and alien values should be reported. Same as above.

✅ The input domain seems correct to me, since it should be a string or null and alien values should be reported. Same as above.

✅ The input domain seems correct to me, since it should be a string or null and alien values should be reported. Same as above.

✅ It's OK to assume a PHID as string or as NULL (default). Alien values will be reported and this is OK.