### Question:
NormalDistribution extends AbstractContinuousDistribution { @Override public double density(double x) { return Math.exp(logDensity(x)); } NormalDistribution(double mean,
                              double sd); double getStandardDeviation(); @Override double density(double x); @Override double logDensity(double x); @Override double cumulativeProbability(double x); @Override double inverseCumulativeProbability(final double p); @Override double probability(double x0,
                              double x1); @Override double getMean(); @Override double getVariance(); @Override double getSupportLowerBound(); @Override double getSupportUpperBound(); @Override boolean isSupportConnected(); @Override ContinuousDistribution.Sampler createSampler(final UniformRandomProvider rng);  }### Answer:
@Test void testDensity() { final double[] x = new double[] {-2, -1, 0, 1, 2}; checkDensity(0, 1, x, new double[] {0.05399096651, 0.24197072452, 0.39894228040, 0.24197072452, 0.05399096651}); checkDensity(1.1, 1, x, new double[] {0.003266819056, 0.043983595980, 0.217852177033, 0.396952547477, 0.266085249899}); }