public function containsId($id, string $rootClassName) : bool
    {
        return isset($this->identityMap[$rootClassName][serialize($id)]);
    }
public function containsId($id, string $rootClassName) : bool
    {
        return isset($this->identityMap[$rootClassName][serialize($id)]);
    }
public function containsId ( $ id , string $ rootClassName ) : bool { return isset ( $ this -> identityMap [ $ rootClassName ] [ serialize ( $ id ) ] ) ; }
Checks whether an identifier exists in the identity map.

@internal
Checks whether an identifier exists in the identity map .