* variables.
 *
 * <p><a id="bitEquals"></a>This class compares primitive {@code double} values in methods such as
 * {@link #compareAndSet} by comparing their bitwise representation using {@link
 * Double#doubleToRawLongBits}, which differs from both the primitive double {@code ==} operator and
 * from {@link Double#equals}, as if implemented by:
 *
 * {@snippet :
 * static boolean bitEquals(double x, double y) {