function getSingle($type_uri, $default = null)
{
$values = Auth_OpenID::arrayGet($this->data, $type_uri);
if (!$values) {
return $default;
} else {
if (count($values) == 1) {
return $values[0];
} else {
return new Auth_OpenID_AX_Error(sprintf('More than one value present for %s', $type_uri));
}
}
}