getColorLookupTable function Null safety

Map<int, String> getColorLookupTable()

Implementation

Map<int, String> getColorLookupTable() {
  if (_table == null) {
    var m = <int, String>{};
    for (var x in CLUT) {
      m[x[0]] = x[1];
    }
    _table = m;
  }
  return _table!;
}