clear method
void
clear()
Implementation
void clear() {
if (_length == 0) return;
final membership = _membership;
for (var dense = 0; dense < _length; dense++) {
final entityIndex = _denseEntities[dense];
_sparse[entityIndex] = 0;
membership?.remove(entityIndex, _membershipId);
clearPayload(dense);
}
_length = 0;
bumpRevision();
_changeListener?.cleared();
}