protected function _getAuthenticatorsForAgent()
{
if (!($mode = strtolower($this->_auth_mode))) {
return $this->_authenticators;
}
foreach ($this->_authenticators as $authenticator) {
if (strtolower($authenticator->getAuthKeyword()) == $mode) {
return array($authenticator);
}
}
throw new Swift_TransportException('Auth mode ' . $mode . ' is invalid');
}