private void DumpLogToFile_()
 {
     while (IsOpen)
     {
         waitHandle_.WaitOne(2000);
         if (FilePath == null)
         {
             continue;
         }
         if (queue_.Count > 0)
         {
             string[] logLines;
             lock (queue_)
             {
                 logLines = queue_.ToArray();
                 queue_.Clear();
             }
             lock (FilePath)
             {
                 FileUtils.AppendToTextFile(FilePath, logLines);
             }
             Thread.Sleep(1000);
         }
     }
 }