Opted for using Optionals in the game state!
Opted for the use of Optional.
Refactoring.
Refactoring; fixed active block in the gridToAscii method.
Refactoring.
Removed unnecessary autoboxing.
Using Optionals instead of null values for groups to be updated.
Using an Optional for the previous value.
Using an Optional for the previous state.
Using Optionals for blocks in the grid.