code/libraries/joomlatools/library/object/registry/cache.php
public function offsetExists($offset)
    {
        if(false === $result = parent::offsetExists($offset)) {
            $result = apc_exists($this->getNamespace().'-object_'.$offset);
        }

        return $result;
    }
public function offsetExists($offset)
    {
        if(false === $result = parent::offsetExists($offset)) {
            $result = apc_exists($this->getNamespace().'-object_'.$offset);
        }

        return $result;
    }
public function offsetExists ( $ offset ) { if ( false === $ result = parent :: offsetExists ( $ offset ) ) { $ result = apc_exists ( $ this -> getNamespace ( ) . '-object_' . $ offset ) ; } return $ result ; }
Check if the offset exists

@param   int     $offset The offset
@return  bool
Check if the offset exists