private void bw_DoWork(object sender, DoWorkEventArgs e)
{
BackgroundWorker loadWorker = sender as BackgroundWorker;
index = new InvertedIndex();
logic = new Expressions(index, persistentFileName);
logEntries = new LogEntries(logFilename, index, ProgressUpdate);
if (logEntries!=null)
{
logEntries.Build();
}
}