code: @Override
      public String getSQL() {
  
          if (userTypeModifier == null) {
              throw Error.runtimeError(ErrorCode.U_S0500, "Type");
          }
  
          return userTypeModifier.getSQL();
      }
docs: Retrieves the SQL character sequence required to (re)create the
  trigger, as a StringBuffer
  
  @return the SQL character sequence required to (re)create the
  trigger