/**
* verifica se a chave informada e valida e a retorna
*
* @param string $key
* @return string
* @throws IllegalArgumentException
* */
public static function isValidKey($key)
{
$key = trim($key);
if (!$key) {
throw IllegalArgumentException::argumentCantBeNULL("key: {$key}");
}
return $key;
}
