/**
* Get object offset
*
* @param string $ref
* @return integer
*/
public function getOffset($ref)
{
if (isset($this->_inuse[$ref])) {
return $this->_inuse[$ref];
}
if (isset($this->_free[$ref])) {
return null;
}
if (isset($this->_parent)) {
return $this->_parent->getOffset($ref);
}
return null;
}
