def test_send_to_all():
    conns = [mock.Mock() for i in range(10)]
    c = Connections('test', 'dummy')
    for i in conns:
        c._add(i, id(i))

    c.send_to_all('foo')
    for i in conns:
        assert i.send_concurrent.called
        i.send_concurrent.assert_called_with(('test', 'dummy', 'foo'))