diff --git a/storage/storage.go b/storage/storage.go
index 7d521eb0..51f0b9c0 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -33,5 +33,8 @@ type StorageDriver interface {
 	// should return at most numSamples samples.
 	Samples(containername string, numSamples int) ([]*info.ContainerStatsSample, error)
 
+	// Close will clear the state of the storage driver. The elements
+	// stored in the underlying storage may or may not be deleted depending
+	// on the implementation of the storage driver.
 	Close() error
 }
diff --git a/storage/test/storagetests.go b/storage/test/storagetests.go
index ed460705..ec9f5934 100644
--- a/storage/test/storagetests.go
+++ b/storage/test/storagetests.go
@@ -59,10 +59,8 @@ func StorageDriverTestSampleCpuUsage(driver storage.StorageDriver, t *testing.T)
 
 	// We need N+1 observations to get N samples
 	for i := 0; i < N+1; i++ {
-		cpuusage := uint64(rand.Intn(1000))
-		memusage := uint64(rand.Intn(1000))
-		cpuTrace = append(cpuTrace, cpuusage)
-		memTrace = append(memTrace, memusage)
+		cpuTrace = append(cpuTrace, uint64(rand.Intn(1000)))
+		memTrace = append(memTrace, uint64(rand.Intn(1000)))
 	}
 
 	samplePeriod := 1 * time.Second