### Question:
GaussianSampler implements Sampler<Double> { public Double sample() { return rng.nextGaussian() * std + mean; } GaussianSampler(double mean, double std, SeedFactory seedFactory); Double sample();  }### Answer:
@Test public void testSample() throws Exception { double mean = 2.0; double var = 1.0; SeedFactory seedFactory = new SeedFactory(1234); Sampler<Double> sampler = new GaussianSampler(mean, var, seedFactory); Double result = sampler.sample(); assertTrue(result >= -10); assertTrue(result <= 10); }