insertKey method
Inserts key's nid at visible position index. key must be
registered.
Implementation
void insertKey(int index, TKey key) {
insertNid(index, _nids[key]!);
}
Inserts key's nid at visible position index. key must be
registered.
void insertKey(int index, TKey key) {
insertNid(index, _nids[key]!);
}