public function getFirstChild($role=null, $type=null, $values=null, $properties=null, $useRegExp=true) {
    $children = $this->getChildrenEx(null, $role, $type, $values, $properties, $useRegExp);
    if (sizeof($children) > 0) {
      return $children[0];
    }
    else {
      return null;
    }
  }