code: public void walk(ChuckWalker walker) {
          Object chunk;
          for (int i = 0, len = this.children.size(); i < len; i++) {
              chunk = this.children.get(i);
              if (chunk instanceof SourceNode) {
                  ((SourceNode) chunk).walk(walker);
              } else {
                  if (((String) chunk).length() != 0) {
                      walker.walk((String) chunk, new OriginalPosition(this.line, this.column, this.source, this.name));
                  }
              }
          }
      }
docs: Walk over the tree of JS snippets in this node and its children. The walking function is called once for each snippet of JS and is passed that
  snippet and the its original associated source's line/column location.
  
  @param aFn
  The traversal function.