public void Close()
        {
            if (state != ConnectionState.Open)
            {
                return;
            }

            state = ConnectionState.Closed;

            if (Version == 3)
            {
                //Sqlite3.sqlite3_close()
                Sqlite3.Close2(sqlite_handle2);
            }
            //else
            //Sqlite.sqlite_close (sqlite_handle);
            sqlite_handle = IntPtr.Zero;
        }