def use_json(self, *paths):
        """
        Args:
            *paths (str | unicode): Paths to files to add as static DictProvider-s, only existing files are added
        """
        for path in paths:
            if path:
                fpath = os.path.expanduser(path)
                if os.path.exists(fpath):
                    with open(fpath) as fh:
                        provider = DictProvider(json.load(fh), name=path)
                        self.add(provider)