public Set<String> getConnectionIdentifiers() {
        return connectionIdentifiers;
    }
Returns the identifiers of all readable child connections within this
connection group. This is set only when the parent connection group is
queried, and has no effect when a connection group is inserted, updated,
or deleted.

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