Get the handler object for a single handler.
public function &getHandler($type, $id) {
if (!isset($this->handlers[$type])) {
$this
->getHandlers($type);
}
if (isset($this->handlers[$type][$id])) {
return $this->handlers[$type][$id];
}
// So we can return a reference.
$null = NULL;
return $null;
}