/// <summary> /// Returns a collection cursor. /// </summary> /// <typeparam name="TDocument">The type representing a Document.</typeparam> /// <param name="filter">A LINQ expression filter.</param> /// <param name="partitionKey">An optional partition key.</param> public IFindFluent <TDocument, TDocument> GetCursor <TDocument>(Expression <Func <TDocument, bool> > filter, string partitionKey = null) where TDocument : IDocument <TKey> { return(MongoDbReader.GetCursor <TDocument, TKey>(filter, partitionKey)); }