private void RemoveUsedPossibilities()
{
for (var x = 0; x < Game.SudokuSize; x++)
{
for (var y = 0; y < Game.SudokuSize; y++)
{
var cellValue = CellsSolution[x, y];
if (cellValue != SudokuElementSolution.InvalidValue)
{
var elementsAtCell = GetSudokuElements(x, y);
SudokuElementSolution.RemovePossibility(elementsAtCell, cellValue);
}
}
}
}