public static uint GetFirstValue(this FixedSizeNode <SnapUInt32, SnapUInt32> tree)
        {
            SnapUInt32 k = new SnapUInt32();
            SnapUInt32 v = new SnapUInt32();

            tree.TryGetFirstRecord(k, v);
            return(v.Value);
        }
        public static void GetFirstKeyValue(this FixedSizeNode <SnapUInt32, SnapUInt32> tree, out uint key, out uint value)
        {
            SnapUInt32 k = new SnapUInt32();
            SnapUInt32 v = new SnapUInt32();

            tree.TryGetFirstRecord(k, v);
            key   = k.Value;
            value = v.Value;
        }