code: public void write( Object data, Map<String, Object> output, WalkedPath walkedPath ) {
          List<String> evaledPaths = evaluate( walkedPath );
          if ( evaledPaths != null ) {
              traversr.set( output, evaledPaths, data );
          }
      }
docs: Use the supplied WalkedPath, in the evaluation of each of our PathElements to
  build a concrete output path.  Then use that output path to write the given
  data to the output.
  
  @param data data to write
  @param output data structure we are going to write the data to
  @param walkedPath reference used to lookup reference values like "&1(2)"