req         *http.Request
		expectedErr error
	}{
		// Set valid authorization header.
		{
			req: &http.Request{
				Header: http.Header{
					"Authorization": []string{token},
				},
			},
			expectedErr: nil,
		},
		// No authorization header.
		{
			req: &http.Request{
				Header: http.Header{},
			},
			expectedErr: errNoAuthToken,
		},
		// Invalid authorization token.
		{