code: boolean assertConnection() {
      try {
        if (getDatabaseConnection() == null
            || getDatabaseConnection().connection == null) {
          return error(loc("no-current-connection"));
        }
  
        if (getDatabaseConnection().connection.isClosed()) {
          return error(loc("connection-is-closed"));
        }
      } catch (SQLException sqle) {
        return error(loc("no-current-connection"));
      }
  
      return true;
    }
docs: Assert that we have an active, living connection. Print an error message
  if we do not.
  
  @return true if there is a current, active connection