// Pusher overrides this to implement the .createTarget option
/// <summary>This is the _local document ID stored on the remote server to keep track of state.
/// </summary>
/// <remarks>
/// This is the _local document ID stored on the remote server to keep track of state.
/// Its ID is based on the local database ID (the private one, to make the result unguessable)
/// and the remote database's URL.
/// </remarks>
internal String RemoteCheckpointDocID()
{
if (LocalDatabase == null)
{
return(null);
}
var input = LocalDatabase.PrivateUUID() + "\n" + RemoteUrl + "\n" + (!IsPull ? "1" : "0");
return(Misc.TDHexSHA1Digest(Runtime.GetBytesForString(input)));
}