reset method
void
reset()
Lepas ikatan ke koleksi manapun (dipanggil saat pindah source/koleksi).
Implementation
void reset() {
_boundSourceId = null;
_boundCollection = null;
columns = [];
columnsTable = null;
searchText = '';
sortColumn = null;
sortAscending = true;
_disposePagination();
notifyListeners();
}