@Override
    public String getIdentifier() {

        // If no associated ID, then no associated identifier
        Integer id = getObjectID();
        if (id == null)
            return null;

        // Otherwise, the identifier is the ID as a string
        return id.toString();

    }
Sets the identifiers of all readable child connection groups within this
connection group. This should be set only when the parent connection
group is queried, as it has no effect when a connection group is
inserted, updated, or deleted.

@param connectionGroupIdentifiers
    The identifiers of all readable child connection groups within this
    connection group.
extensions/guacamole-auth-jdbc/modules/guacamole-auth-jdbc-base/src/main/java/org/apache/guacamole/auth/jdbc/connectiongroup/ConnectionGroupModel.java