public function __construct($name, $ns = '', $attrs = [], $data = '')
{
$this->name = strtolower($name);
$this->ns = $ns;
if (is_array($attrs) && count($attrs)) {
foreach ($attrs as $key => $value) {
$this->attrs[strtolower($key)] = $value;
}
}
$this->data = $data;
}