code: public JSON with(PrettyPrinter pp)
      {
          if (_prettyPrinter == pp) {
              return this;
          }
          return _with(_features, _streamFactory, _treeCodec,
                  _reader, _writer, pp);
      }
docs: Mutant factory for constructing an instance with specified {@link PrettyPrinter},
  and returning new instance (or, if there would be no change, this instance).