### Question:
AtomicDouble extends Number { public void set(double amount) { value.set(Double.doubleToLongBits(amount)); } AtomicDouble();  AtomicDouble(double init); double get(); double addAndGet(double amount); double getAndAdd(double amount); double getAndSet(double amount); boolean compareAndSet(double expect, double update); void set(double amount); void max(double v); @Override int intValue(); @Override long longValue(); @Override float floatValue(); @Override double doubleValue();  }### Answer:
@Test public void set() { AtomicDouble v = new AtomicDouble(13.0); v.set(42.0); Assertions.assertEquals(42.0, v.get(), 1e-12); }