public function getMulti(array $keys, array &$tokens = null)
{
$results = array();
$tokens = array();
foreach ($keys as $key) {
$token = null;
$value = $this->get($key, $token);
if ($token !== null) {
$results[$key] = $value;
$tokens[$key] = $token;
}
}
return $results;
}