Combining Filters in QueryInterceptor

   In my QueryInterceptor, I add several filters.  The issue is that only one filter is allowed.

So I am trying to check and see if an existing filter exists, and if it does, add a second PredicateDescription to it.

    if (typeof(IDeletable).IsAssignableFrom(Query.QueryableType)) {

                var deleteFilter = new PredicateDescription(Query.QueryableType, "IsDeleted", FilterOperator.IsEqualTo, false);

                var existingFilter = QueryFilters.GetFilterQueryForType(Query.QueryableType);

                if (existingFilter != null) {

                    var combinedFilter = //Combine Filters Here

                    QueryFilters.AddFilter(combinedFilter, true);

                }

                else {

                    QueryFilters.AddFilter(deleteFilter);

                }       

            }

But I don't see a way to do this.

Greg