assertNull(pt.horizontalSymmetry(null));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(Double.NaN, 1.)));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(1., Double.NaN)));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(Double.POSITIVE_INFINITY, 1.)));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(1., Double.POSITIVE_INFINITY)));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(Double.NEGATIVE_INFINITY, 1.)));
assertNull(pt.horizontalSymmetry(ShapeFactory.createPoint(1., Double.NEGATIVE_INFINITY)));
assertEquals(pt.horizontalSymmetry(ShapeFactory.createPoint(0.,0.)), ShapeFactory.createPoint(-10., 10.));
assertEquals(pt.horizontalSymmetry(ShapeFactory.createPoint(0.,18780.)), ShapeFactory.createPoint(-10., 10.));
assertEquals(ShapeFactory.createPoint(-10., 10.).horizontalSymmetry(ShapeFactory.createPoint(0.,18780.)), pt);
assertEquals(ShapeFactory.createPoint(0.,0.).horizontalSymmetry(ShapeFactory.createPoint(0.,0.)), ShapeFactory.createPoint(0., 0.));