def get_metadata(self, container, prefix=None):
        """
        Returns a dictionary containing the metadata for the container.
        """
        headers = self.get_headers(container)
        if prefix is None:
            prefix = CONTAINER_META_PREFIX
        low_prefix = prefix.lower()
        ret = {}
        for hkey, hval in list(headers.items()):
            if hkey.lower().startswith(low_prefix):
                cleaned = hkey.replace(low_prefix, "").replace("-", "_")
                ret[cleaned] = hval
        return ret