docs: def disconnect(filename=None):
      """
      Connect to the local cache, so no internet connection is required.
      :returns: void
      """
      global _CONNECTED
      if filename is not None:
          try:
              with open(filename, 'r') as f:
                  _load_from_string(f.read())
          except FileNotFoundError:
              raise USGSException("""The cache file '{0}' was not found, and I cannot disconnect without one. If you have not been given a cache.json file, then you can create a new one:
          >>> from earthquakes import earthquakes
          >>> earthquakes.connect()
          >>> earthquakes._start_editing()
          ...
          >>> earthquakes.get_report()
          ...
          >>> earthquakes._save_cache('{0}')""".format(filename))
      for key in _CACHE.keys():
          _CACHE_COUNTER[key] = 0
      _CONNECTED = False