@Override
  public String toString() {
    synchronized (lock) {
      FastStringBuffer buffer = new FastStringBuffer();
      buffer.append("AdditionalInfo{");

      buffer.append("topLevel=[");
      entrySetToString(buffer, this.topLevelInitialsToInfo.entrySet());
      buffer.append("]\n");
      buffer.append("inner=[");
      entrySetToString(buffer, this.innerInitialsToInfo.entrySet());
      buffer.append("]");

      buffer.append("}");
      return buffer.toString();
    }
  }