return nil, fmt.Errorf("duplicate endpoints found")
		}
		uniqueArgs.Add(arg)
		endpoints = append(endpoints, endpoint)
	}

	return endpoints, nil
}

// Checks if there are any cross device mounts.
func checkCrossDeviceMounts(endpoints Endpoints) (err error) {
	var absPaths []string
	for _, endpoint := range endpoints {
		if endpoint.IsLocal {
			var absPath string

	}
	b1.Flush()
	if w1 != 3 {
		t.Fatalf("flush 1200 + 1389 'x's: got %d writes, want 3", w1)
	}
}

// A writeCountingDiscard is like io.Discard and counts the number of times
// Write is called on it.
type writeCountingDiscard int

func (w *writeCountingDiscard) Write(p []byte) (int, error) {
	*w++
	return len(p), nil
}

type negativeReader int