gistfile1.cs

//CODE in project
Facility.AddIndex(f => f.Locations);
LookupMetadata.AddIndex(f => new {f.TypeFullName, f.Data.DisplayText});


//CODE in library
        public void AddIndex(Expression<Func<T, object>> indexKey, string indexName = null, bool isUnique = false, bool descending = false)
        {
            if (string.IsNullOrEmpty(indexName))
            {
                indexName = typeof(T).Name + "_Index_" + ObjectId.GenerateNewId();
            }

            // TODO: Make indexKey into a CSV string?
            var keys = indexKey......

            var keys = IndexKeys.Ascending(keys);
            var options = IndexOptions.SetName(indexName).SetUnique(isUnique);

            this.GetMongoCollection().CreateIndex(keys, options);
        }