private function escape($arguments)
{
$args = array();
foreach ($arguments as $k => $v) {
if (is_array($v)) {
$args[$k] = $this->escape($v);
} elseif (is_string($v)) {
$args[$k] = str_replace('%', '%%', $v);
} else {
$args[$k] = $v;
}
}
return $args;
}