    @Test
    public void testOmni() throws Exception {

        Random cx = new Random();
        for (int i = 0; i < 20; i++) {
            double x = cx.nextDouble() * 20;
            double y = cx.nextDouble() * 20;
            Antenna ax = Antenna.omni(x, y);
            ax.setPower(100, 0.01);
            checkInvariants(ax, x, y);
        }
    }