code: protected final void map(Object source, Object destination) {
      assertBuilder();
      builder.map(source, destination);
    }
docs: Defines a mapping from the {@code source} to the {@code destination}. See the See the <a
  href="#0">EDSL examples</a>.
  
  @param source to map from
  @param destination to map to
  @throws IllegalStateException if called from outside the context of
  {@link PropertyMap#configure()}.