Retrofit callbacks are not getting trigerred : Retrofit callbacks are not getting called.My code is-:

Call<OpShiftModel[]> tabCall = opShiftService.getTabData(getAuthHeader());
        tabCall.enqueue(new Callback<OpShiftModel[]>() {

            @Override
            public void onResponse(Call<OpShiftModel[]> call, Response<OpShiftModel[]> response) {
                try {
                    listener.onSuccess(response.body());
                } catch (NullPointerException e) {
                    onFailure(call, e);
                }
            }

            @Override
            public void onFailure(Call<OpShiftModel[]> call, Throwable throwable) {

            }
        });}

Http response is coming successfull although.