func TestFailedRefreshLock(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	// Simulate Refresh response to return no locking found
	for i := range lockServers[:3] {
		lockServers[i].setRefreshReply(false)
		defer lockServers[i].setRefreshReply(true)
	}

	dm := NewDRWMutex(ds, "aap")
	dm.refreshInterval = 500 * time.Millisecond