@Test
public void testBadRequestResponseForInvalidExpandParameterRequests(TestContext context) {

    expansionHandler = new ExpansionHandler(vertx, storage, httpClient, new HashMap<>(), ROOT, RULES_ROOT);
    CaseInsensitiveHeaders params = new CaseInsensitiveHeaders();
    params.set(EXPAND_PARAM, "foo");
    HttpServerResponse response = Mockito.mock(HttpServerResponse.class);
    Request request = new Request(HttpMethod.GET, "/some/expandRequest/uri", params, response);
    expansionHandler.handleExpansionRecursion(request);
    verify(response, times(1)).setStatusCode(StatusCode.BAD_REQUEST.getStatusCode());
    verify(response, times(1)).setStatusMessage(StatusCode.BAD_REQUEST.getStatusMessage());
    verify(response, times(1)).end("Expand parameter is not valid. Must be a positive number");
    verifyZeroInteractions(httpClient);
}