public void deleteKid(Node<K, V> obj) {
int index = kids.indexOf(obj);
if (index == 0) {
guides.remove(index);
kids.remove(index);
} else if (index > 0) {
guides.remove(index - 1);
kids.remove(index);
}
if (isUnderHalfFull()) {
merge();
}
}
