Connect to the local cache, so no internet connection is required.
    :returns: void

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