code: @NullSafe
    @Override
    public Visitor compose(Visitor one, Visitor two) {
  
      Optional.ofNullable(one).ifPresent(this::add);
      Optional.ofNullable(two).ifPresent(this::add);
  
      return this;
    }
docs: Compose the given {@link Visitor} objects into a {@link Composite} object.
  
  @return a {@link Visitor} {@link Composite} object composed of the given {@link Visitor} objects
  as an instance of {@link Visitor}.
  @see org.cp.elements.lang.Visitor