Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of reference types in type of parameter 'x' of 'int DeviceComparer.Compare(object x, object y)' doesn't match implicitly implemented member 'int IComparer.Compare(object? x, object? y)' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'y' of 'int DeviceComparer.Compare(object x, object y)' doesn't match implicitly implemented member 'int IComparer.Compare(object? x, object? y)' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'x' of 'int ScreenComparer.Compare(object x, object y)' doesn't match implicitly implemented member 'int IComparer.Compare(object? x, object? y)' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'y' of 'int ScreenComparer.Compare(object x, object y)' doesn't match implicitly implemented member 'int IComparer.Compare(object? x, object? y)' (possibly because of nullability attributes).

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.

Possible null reference return.