removeRange method
Removes entries in [start, end), shifting the suffix left.
Implementation
void removeRange(int start, int end) {
final n = end - start;
if (n <= 0) {
return;
}
final cb = _onNidRemoved;
if (cb != null) {
for (int i = start; i < end; i++) {
cb(_orderNids[i]);
}
}
// memmove: shift [start + n, _len) to [start, _len - n).
_orderNids.setRange(start, _len - n, _orderNids, start + n);
_len -= n;
_onMutated();
}