code: def createFileList(self):
          
          global childFileListDownload
          if childFileListDownload is None or not childFileListDownload.is_alive():
              childFileListDownload = multiprocessing.Process(target=self.createFileListHTTP)
              childFileListDownload.start()
docs: SRTM data is split into different directories, get a list of all of
              them and create a dictionary for easy lookup.