'Removes the source path if it exists, then re-expands the archive.'

@_needs_stage
def reset(self):

    if (not self.archive_file):
        raise NoArchiveFileError('Tried    to    reset    URLFetchStrategy    before    fetching', ('Failed    on    reset()    for    URL    %s' % self.url))
    for filename in os.listdir(self.stage.path):
        abspath = os.path.join(self.stage.path, filename)
        if (abspath != self.archive_file):
            shutil.rmtree(abspath, ignore_errors=True)
    self.expand()
