in src/Credentials/Providers/CredentialsProvider.php [25:40]
public static function chain()
{
$providers = func_get_args();
if (empty($providers)) {
throw new ClientException('No providers in chain', SDK::INVALID_ARGUMENT);
}
foreach ($providers as $provider) {
if (!$provider instanceof Closure) {
throw new ClientException('Providers must all be Closures', SDK::INVALID_ARGUMENT);
}
}
self::$customChains = $providers;
}