remove method
Remove all entries whose rowid equals rowid. Returns the number of
entries removed. After a deletion the tree may be slightly suboptimal
but remains correct.
Implementation
int remove(int rowid) {
final removed = _remove(_root, rowid);
// If the root has a single child after a deletion, collapse it.
while (!_root.isLeaf && _root.entries.length == 1) {
_root = _root.entries.first.child!;
}
return removed;
}