close method Null safety
Implementation
List<int> close() {
  return [
    ((_hash >> 24) & 0xFF),
    ((_hash >> 16) & 0xFF),
    ((_hash >> 8) & 0xFF),
    (_hash & 0xFF)
  ];
}List<int> close() {
  return [
    ((_hash >> 24) & 0xFF),
    ((_hash >> 16) & 0xFF),
    ((_hash >> 8) & 0xFF),
    (_hash & 0xFF)
  ];
}