sub handle_something {
    my ( $kernel, $heap ) = @_[ KERNEL, HEAP ];
    $kernel->post(
        $heap->{ 'messaging_session_id' },
        'unsubscribe_all',
    );
    $kernel->post(
        $heap->{ 'messaging_session_id' },
        'subscribe' => '/some/message/queue',
    );
}