protected override void ReadContent(LiteDB.ByteReader reader)
        {
            var info = reader.ReadString(HEADER_INFO.Length);
            var ver = reader.ReadByte();

            this.ChangeID = reader.ReadUInt16();
            this.FreeEmptyPageID = reader.ReadUInt32();
            this.LastPageID = reader.ReadUInt32();
            this.DbVersion = reader.ReadUInt16();
            this.Password = reader.ReadBytes(this.Password.Length);

            // read page collections references (position on end of page)
            var cols = reader.ReadByte();
            for (var i = 0; i < cols; i++)
            {
                this.CollectionPages.Add(reader.ReadString(), reader.ReadUInt32());
            }
        }
        protected override void ReadContent(LiteDB.ByteReader reader)
        {
            this.CollectionName = reader.ReadString();
            this.FreeDataPageID = reader.ReadUInt32();
            var uintCount = reader.ReadUInt32(); // read as uint (4 bytes)

            foreach (var index in this.Indexes)
            {
                index.Field = reader.ReadString();
                index.HeadNode = reader.ReadPageAddress();
                index.TailNode = reader.ReadPageAddress();
                index.FreeIndexPageID = reader.ReadUInt32();
                index.Options.Unique = reader.ReadBoolean();
                index.Options.IgnoreCase = reader.ReadBoolean();
                index.Options.TrimWhitespace = reader.ReadBoolean();
                index.Options.EmptyStringToNull = reader.ReadBoolean();
                index.Options.RemoveAccents = reader.ReadBoolean();
            }

            // be compatible with v2_beta
            var longCount = reader.ReadInt64();
            this.DocumentCount = Math.Max(uintCount, longCount);

        }
        protected override void ReadContent(LiteDB.ByteReader reader)
        {
            this.DataBlocks = new Dictionary<ushort, DataBlock>(ItemCount);

            for (var i = 0; i < ItemCount; i++)
            {
                var block = new DataBlock();

                block.Page = this;
                block.Position = new LiteDB.PageAddress(this.PageID, reader.ReadUInt16());
                block.ExtendPageID = reader.ReadUInt32();

                for (var j = 0; j < CollectionIndex.INDEX_PER_COLLECTION; j++)
                {
                    block.IndexRef[j] = reader.ReadPageAddress();
                }

                var size = reader.ReadUInt16();
                block.Data = reader.ReadBytes(size);

                this.DataBlocks.Add(block.Position.Index, block);
            }
        }