public function zAdd($key, $score, $member = NULL)
{
if (!is_array($score)) {
$values = func_get_args();
} else {
foreach ($score as $score_value => $member) {
$values[] = $score_value;
$values[] = $member;
}
array_unshift($values, $key);
}
return $this->__call('zadd', $values);
}