private static void MockManualContext(IsolationUtils.TestAction action, string returns = null)
        {
            var  clientMock = new Mock <IFaunaClient>();
            var  context    = IsolationUtils.CreateMappingContext(clientMock.Object);
            Expr lastQuery  = null;

            clientMock.Setup(a => a.Query(It.IsAny <Expr>())).Returns((Expr q) =>
            {
                lastQuery = q;
                return(Task.FromResult(new RequestResult(
                                           HttpMethod.Get,
                                           "",
                                           new Dictionary <string, string>(),
                                           "",
                                           returns,
                                           400,
                                           new Dictionary <string, IEnumerable <string> >(),
                                           DateTime.Now,
                                           DateTime.Now
                                           )));
            });

            action(context, ref lastQuery);
        }