public function transform(Assertion $assertion)
{
if (!$this->identityProvider->hasBase64EncodedAttributes()) {
return $assertion;
}
$attributes = $assertion->getAttributes();
$keys = array_keys($attributes);
$decoded = array_map(array($this, 'decodeValue'), $attributes);
$attributes = array_combine($keys, $decoded);
$assertion->setAttributes($attributes);
}