for i, testCase := range testCases {
		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		req, lerr := newTestSignedRequestV4(http.MethodGet, getListBucketURL(""), 0, nil, testCase.accessKey, testCase.secretKey, nil)
		if lerr != nil {
			t.Fatalf("Test %d: %s: Failed to create HTTP request for ListBucketsHandler: <ERROR> %v", i+1, instanceType, lerr)
		}