public async Task Backup(BackupOptions options = BackupOptions.None, IEnumerable <string> packages = null, string backupFile = null, CancellationToken cancellationToken = default(CancellationToken))
{
string fileString = backupFile != null?string.Format("-f {0}", backupFile.QuoteIfNeeded()) : "";
string packagesString = "";
if (packages != null)
{
packagesString = packages.Aggregate("", (acc, p) => acc + " " + p);
}
await new Adb(this, "backup {0} {1} {2}", fileString, options.GenerateString(), packagesString).RunAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
}
