response, err = s.client.Do(request)

	c.Assert(err, nil)
	// assert the http response status code.
	c.Assert(response.StatusCode, http.StatusOK)

	request, err = newTestSignedRequest(http.MethodHead, getHeadObjectURL(s.endPoint, bucketName, "my-object-directory/"),
		0, nil, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)

	// execute the HTTP request.
	response, err = s.client.Do(request)

		// initialize HTTP NewRecorder, this records any mutations to response writer inside the handler.
		rec := httptest.NewRecorder()
		// construct HTTP request for Get Object end point.
		req, err := newTestSignedRequestV4(http.MethodHead, getHeadObjectURL("", testCase.bucketName, testCase.objectName),
			0, nil, testCase.accessKey, testCase.secretKey, nil)
		if err != nil {

		"internal",
		"resource-exhausted",
		"unavailable",
	)

	// golang supported methods: https://golang.org/src/net/http/method.go
	supportedMethods = sets.New(
		http.MethodGet,
		http.MethodHead,
		http.MethodPost,
		http.MethodPut,
		http.MethodPatch,
		http.MethodDelete,
		http.MethodConnect,
		http.MethodOptions,
		http.MethodTrace,
	)

		method   string
		ct       *ctHeader // Optional Content-Type header to set.
		wantCT   string
		wantBody string
	}{
		{MethodGet, nil, "text/html; charset=utf-8", "<a href=\"/foo\">Found</a>.\n\n"},
		{MethodHead, nil, "text/html; charset=utf-8", ""},
		{MethodPost, nil, "", ""},
		{MethodDelete, nil, "", ""},
		{"foo", nil, "", ""},
		{MethodGet, &ctHeader{[]string{"application/test"}}, "application/test", ""},