rec := httptest.NewRecorder()
		// construct HTTP request for HEAD bucket.
		req, err := newTestSignedRequestV4(http.MethodHead, getHEADBucketURL("", testCase.bucketName), 0, nil, testCase.accessKey, testCase.secretKey, nil)
		if err != nil {
			t.Fatalf("Test %d: %s: Failed to create HTTP request for HeadBucketHandler: <ERROR> %v", i+1, instanceType, err)
		}