Walk a filesystem, yielding absolute paths to files.

        Arguments:
            fs (FS): A filesystem instance.
            path (str): A path to a directory on the filesystem.

        Yields:
            str: absolute path to files on the filesystem found
            recursively within the given directory.

def files(self, fs, path="/"):
        # type: (FS, Text) -> Iterator[Text]
        """Walk a filesystem, yielding absolute paths to files.

        Arguments:
            fs (FS): A filesystem instance.
            path (str): A path to a directory on the filesystem.

        Yields:
            str: absolute path to files on the filesystem found
            recursively within the given directory.

        """
        _combine = combine
        for _path, info in self._iter_walk(fs, path=path):
            if info is not None and not info.is_dir:
                yield _combine(_path, info.name)