### Question:
SudokuMovementController { void processTapCell(int position) { if (boardManager.getBoard().isValidPosition(position)) { prevSelectedPosition = cellPosition; cellPosition = cellPosition != position ? position : -1; if (cellPosition != -1) { gameActivity.makeCellRed(cellPosition); } if (prevSelectedPosition != -1) { gameActivity.makePrevCellColourOriginal(prevSelectedPosition); } } else { gameActivity.makeInvalidTapMessage(); } } SudokuMovementController(SudokuBoardManager boardManager, SudokuGameActivity gameActivity);   }### Answer:
@Test public void testProcessTapCellInvalidPosition() { SudokuGameActivity gameActivity = mock(SudokuGameActivity.class); User user = mock(User.class); SudokuBoardManager boardManager = new SudokuBoardManager(user, 0); boardManager.getBoard().getCell(0, 0).setToBeFilled(); SudokuMovementController mController = new SudokuMovementController(boardManager, gameActivity); mController.processTapCell(1); verify(gameActivity).makeInvalidTapMessage(); }