fix code

app/src/main/java/sudoku/constraint/BlockConstraint.java

@@ -9,7 +9,7 @@ public class BlockConstraint implements IConstraint{
 	@Override
 	public boolean canBePlaced(final Sudoku s, int x, int y, int newSymbolIndex) {
 		Block bloc = s.getCell(x, y).getBlock();
-		return !bloc.getCells().contains(new Cell(newSymbolIndex));
+		return !bloc.getCells().contains(new Cell(newSymbolIndex) {});
 	}
 
 }