anchor.diff:  
     StringBuffer sb;
     int depth;
  +  /** Prefix for the type passed to the next [openNode()] call. */
  +  String nextTypePrefix;
   
     PrettyPrinter() : sb = new StringBuffer(), depth = 0;
   
  
positive.code:     visitNodeWithChildren(node, "ScriptTag");
    }
  
    visitSend(Send node) {
      visitNodeWithChildren(node, "Send");
    }
  
    visitSendSet(SendSet node) {
      visitNodeWithChildren(node, "SendSet");
    }
  
    visitStringInterpolation(StringInterpolation node) {
  
negative.code:   }
  
    void addTypeWithParams(String type, [Map params]) {
      if (nextTypePrefix !== null) {
        sb.add(nextTypePrefix);
        nextTypePrefix = null;
      }
      sb.add("${type}");
      if (params != null) {
        // TODO(smok): Escape doublequotes in values.
  