public static PositionBound at(final Position position) {
        return new PositionBound(position);
    }
@Test
    public void shouldEqualPosition() {
        final PositionBound bound1 = PositionBound.at(Position.emptyPosition());
        final PositionBound bound2 = PositionBound.at(Position.emptyPosition());
        assertEquals(bound1, bound2);
    }