func TestWriterReadFromMustReturnUnderlyingError(t *testing.T) {
	var wr = NewWriter(writeErrorOnlyWriter{})
	s := "test1"
	wantBuffered := len(s)
	if _, err := wr.WriteString(s); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if err := wr.Flush(); err == nil {
		t.Error("expected flush error, got nil")
	}
	if _, err := wr.ReadFrom(strings.NewReader("test2")); err == nil {

			BucketName:      bucketName,
			ConditionValues: getConditionValues(r, "", cred),
			IsOwner:         owner,
			ObjectName:      "",
			Claims:          cred.Claims,
		}) {
			wr = true
		}

		return rd, wr
	}

	// If etcd, dns federation configured list buckets from etcd.
	var err error
	var buckets []BucketInfo
	if globalDNSConfig != nil && globalBucketFederation {