_, errCode = extractSignedHeaders(signedHeaders, r)
	if errCode != ErrUnsignedHeaders {
		t.Fatalf("Expected the APIErrorCode to %d, but got %d", ErrUnsignedHeaders, errCode)
	}

	// case where the list of signed headers doesn't contain the host field.
	signedHeaders = signedHeaders[2:5]
	// expected to fail with `ErrUnsignedHeaders`.
	_, errCode = extractSignedHeaders(signedHeaders, r)

	if payload != req.Header.Get(xhttp.AmzContentSha256) {
		return cred, "", "", time.Time{}, ErrContentSHA256Mismatch
	}

	// Extract all the signed headers along with its values.
	extractedSignedHeaders, errCode := extractSignedHeaders(signV4Values.SignedHeaders, r)
	if errCode != ErrNone {
		return cred, "", "", time.Time{}, errCode
	}

	cred, _, errCode = checkKeyValid(r, signV4Values.Credential.accessKey)
	if errCode != ErrNone {