### Question:
Position { static double distance(Disk firstPoint, Disk secondPoint) { double a = Math.abs(firstPoint.getPosition().y - secondPoint.getPosition().y); double b = Math.abs(firstPoint.getPosition().x - secondPoint.getPosition().x); return Math.sqrt(a * a + b * b); } Position(double x, double y, double z);  public Double x; public Double y; public Double z; }### Answer:
@Test void distanceTest() { double distance = Position.distance(disk1, disk2); assertEquals(1.4142135623730951, distance); }