title: Why does the empty method appendTo make sense?
body: <p>In java 7 am using the <strong>PropertyChangeEvent</strong> class and suddenly I found this:</p>
  
  <pre><code>/**
   * Returns a string representation of the object.
   *
   * @return a string representation of the object
   *
   * @since 1.7
   */
  public String toString() {
      StringBuilder sb = new StringBuilder(getClass().getName());
      sb.append("[propertyName=").append(getPropertyName());
      appendTo(sb);   // &lt;----HERE
      sb.append("; oldValue=").append(getOldValue());
      sb.append("; newValue=").append(getNewValue());
      sb.append("; propagationId=").append(getPropagationId());
      sb.append("; source=").append(getSource());
      return sb.append("]").toString();
  }
  
  void appendTo(StringBuilder sb) {
  }
  </code></pre>
  
  <p>What is driving me crazy, why calling the method <code>appendTo()</code>?</p>
  
  <p>Especially as that  method is doing nothing?</p>
  
  <p>Does this make any sense that I can not find at 1st sight?</p>