     ///         }
     ///     }
     public struct PrefetchedRowsView: Equatable {
+        // OrderedDictionary so that breadth-first search gives a consistent result
+        // (we preserve the ordering of associations in the request)
         fileprivate var prefetches: OrderedDictionary<String, Prefetch> = [:]
         
         /// True if there is no prefetched associated rows.

    fileprivate struct Prefetch: Equatable {
        // Nil for intermediate associations
        var rows: [Row]?
        var prefetches: OrderedDictionary<String, Prefetch>
    }
    

    ///             print(bookBok) // [id:43, title:"Moby-Dick"]
    ///         }
    ///     }
    public internal(set) var prefetchedRows: PrefetchedRowsView = PrefetchedRowsView()
    
    // MARK: - Building rows
    
