@Override
    public void add(Connection connection) throws GuacamoleException {
        connections.put(connection.getIdentifier(), connection);
    }
Returns the current connection identifier counter and then increments it.

@return
    An int representing the next available connection
    identifier to be used when adding connections.
extensions/guacamole-auth-quickconnect/src/main/java/org/apache/guacamole/auth/quickconnect/QuickConnectDirectory.java