NullValue extends ValueAdapter { @Override public boolean isNull() { return true; } private  NullValue(); @Override boolean isNull(); @Override Object asObject(); @Override String asString(); @Override Type type(); @SuppressWarnings("EqualsWhichDoesntCheckParameterClass") @Override boolean equals( Object obj ); @Override int hashCode(); @Override String toString(); static final Value NULL; }
@Test void shouldBeNull() { assertTrue( NullValue.NULL.isNull() ); }