GroupServlet groupServlet = overideGetJSONFromInputToReturnAValidGroupWithFail();
groupServlet.doPost(request, response);
verify(response).sendError(eq(HttpServletResponse.SC_INTERNAL_SERVER_ERROR), argThat(notNullValue(String.class)));
GroupServlet groupServlet = overideGetJSONFromInputToReturnAValidGroupWithFail();
groupServlet.doPost(request, response);
verify(response).sendError(eq(HttpServletResponse.SC_INTERNAL_SERVER_ERROR), argThat(notNullValue(String.class)));