def load(self, requirements_file=None):
        """Load or reload requirements from a requirements.txt file.

        :param requirements_file: if not given, the filename used from
            initialization will be read again.
        """
        if requirements_file is None:
            requirements_file = self.filename
            if requirements_file is None:
                raise ValueError("no filename provided")
        elif isinstance(requirements_file, text_type):
            requirements_file = Path(requirements_file)
        self.clear()
        with requirements_file.open() as f:
            self.loads(f.read())

        if isinstance(requirements_file, (text_type, Path)):
            self.filename = requirements_file
def test_real_config(self, tempdir):
        config = """
        [pipeline:main]
        pipeline = cache proxy-server

        [app:proxy-server]
        use = egg:swift#proxy

        [filter:cache]
        use = egg:swift#memcache
        """
        config_path = os.path.join(tempdir, 'test.conf')
        with open(config_path, 'w') as f:
            f.write(dedent(config))
        memcache_ring = self._loadapp(config_path)
        # only one server by default
        self.assertEqual(list(memcache_ring._client_cache.keys()),
                         ['127.0.0.1:11211'])
        # extra options
        self.assertEqual(memcache_ring._connect_timeout, 0.3)
        self.assertEqual(memcache_ring._pool_timeout, 1.0)
        # tries is limited to server count
        self.assertEqual(memcache_ring._tries, 1)
        self.assertEqual(memcache_ring._io_timeout, 2.0)