diff --git a/transport_double.go b/transport_double.go
new file mode 100644
index 0000000..b65d5db
--- /dev/null
+++ b/transport_double.go
@@ -0,0 +1,76 @@
+package gophercloud
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"strings"
+)
+
+type transport struct {
+	called         int
+	response       string
+	expectTenantId bool
+	tenantIdFound  bool
+}
+
+func (t *transport) RoundTrip(req *http.Request) (rsp *http.Response, err error) {
+	var authContainer *AuthContainer
+
+	t.called++
+
+	headers := make(http.Header)
+	headers.Add("Content-Type", "application/xml; charset=UTF-8")
+
+	body := ioutil.NopCloser(strings.NewReader(t.response))
+
+	rsp = &http.Response{
+		Status:           "200 OK",
+		StatusCode:       200,
+		Proto:            "HTTP/1.1",
+		ProtoMajor:       1,
+		ProtoMinor:       1,
+		Header:           headers,
+		Body:             body,
+		ContentLength:    -1,
+		TransferEncoding: nil,
+		Close:            true,
+		Trailer:          nil,
+		Request:          req,
+	}
+
+	bytes, err := ioutil.ReadAll(req.Body)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(bytes, &authContainer)
+	if err != nil {
+		return nil, err
+	}
+	t.tenantIdFound = (authContainer.Auth.TenantId != "")
+
+	if t.tenantIdFound != t.expectTenantId {
+		rsp.Status = "500 Internal Server Error"
+		rsp.StatusCode = 500
+	}
+	return
+}
+
+func newTransport() *transport {
+	return &transport{}
+}
+
+func (t *transport) IgnoreTenantId() *transport {
+	t.expectTenantId = false
+	return t
+}
+
+func (t *transport) ExpectTenantId() *transport {
+	t.expectTenantId = true
+	return t
+}
+
+func (t *transport) WithResponse(r string) *transport {
+	t.response = r
+	return t
+}