code: public BackupActivity createBackupActivity( File backupDirectory,
                                                  BackupOptions options ) {
          return new BackupActivity(backupDirectory, documentStore, binaryStore, repositoryCache, options);
      }
docs: Create a new {@link BackupActivity activity} instance that can back up the content of the repository as it exists at the
  time the activity is executed.
  
  @param backupDirectory the directory on the file system into which the backup should be placed; this directory should
  typically not exist
  @param options the {@link org.modeshape.jcr.api.BackupOptions} which customize the behavior of the backup.
  @return the backup activity; never null