/// <summary>
    /// Extension to <see cref="ISyncOnlineFileProvider2"/>.
    /// </summary>
    [ReleasedInterface]
    public interface ISyncOnlineFileProvider3 : ISyncOnlineFileProvider2
    {
        /// <summary>
        /// Method that will be called directly before the file transfer for the specified timing is started.
        /// This method does not replace the existing methods for timings <see cref="SyncOnlineFileTiming.AfterApplicationDownload"/> or <see cref="SyncOnlineFileTiming.OnDemand"/>.
        /// Instead, it is an addon for additional timings like <see cref="SyncOnlineFileTiming.BeforeApplicationDownload"/>.
        /// </summary>
        /// <param name="guidDeviceObject">The guid identifying the device.</param>
        /// <param name="guidApplication">The guid identifying the application.</param>
        /// <param name="timing">The <see cref="SyncOnlineFileTiming"/> used for the download.</param>
        /// <param name="bIsOnlineChange">Will be TRUE if the transfer is for an online change, for a full download FALSE.</param>
        /// <returns>A list of <see cref="ISyncOnlineFile"/> to be downloaded. Return <c>null</c> if there are no files to be downloaded.</returns>
        IList<ISyncOnlineFile> GetSyncFilesFast(Guid guidDeviceObject, Guid guidApplication, SyncOnlineFileTiming timing, bool bIsOnlineChange);
    }