code: public static String getIdString(Object object) {
  		if (object == null) {
  			throw new NullPointerException();
  		}
  		return String.valueOf(getId(object));
  	}
docs: Get the value of the <code>id</code> field as String
  
  @param object object containing the id. Must not be <code>null</code>
  @return the value of the <code>id</code> field as String