public ConnectionMultiplexerSession getMultiplexerSession(String connectionManagerDomain) {
        return getMultiplexerSession(connectionManagerDomain,null);
    }
Returns a {@link ConnectionMultiplexerSession} for the specified connection manager
domain or {@code null} if none was found. In case the connection manager has many
connections established with the server then one of them will be selected randomly.

@param connectionManagerDomain the domain of the connection manager to get a session.
@return a session to the specified connection manager domain or null if none was found.
xmppserver/src/main/java/org/jivesoftware/openfire/multiplex/ConnectionMultiplexerManager.java