code: public static String addInternalActionId(String actionId, String internalActionId)
      {
          if (actionId == null)
          {
              return internalActionId + INTERNAL_ACTION_ID_DELIMITER;
          }
          return internalActionId + INTERNAL_ACTION_ID_DELIMITER + actionId;
      }
docs: Adds the internal action id to the given action id.
  
  @param actionId the action id as set by the user.
  @param internalActionId the internal action id to add.
  @return the action id prefixed by the internal action id suitable to be
  sent to Asterisk.