@Override
	public ValidationResult validateMaze(Maze maze) {
		int humen = 0;
		for (Room room : maze.getRooms()) {
			if (room.inner() instanceof Human)
				humen++;
			// Arrows can't contain crates
			if (room instanceof Arrow && room.inner() instanceof Crate)
				return new ValidationResult("There can't be crates on arrows, or arrows under crates");
			// Walls can't contain anything
			if (room instanceof Wall && !(room.inner() instanceof Nothing))
				return new ValidationResult("There can't be anything on walls, or walls under anything");
		}
		// We can't have more than two humen
		if (humen > 1)
			return new ValidationResult("There can't be more than one player in the maze");
		// Otherwise everything is good!
		return new ValidationResult();
	}