def _create_movie_tiles(movies, tile_template):
    """Return a string containing unique HTML for each movie.

    Args:
        movies (list[Movie]): The movies for which to render content.
        tile_template (str): The template string to be used with
                             `str.format()`.  It should include references
                             in curly braces to movie attributes, such as
                             "{movie.title}".

    Returns:
        str: The concatenation of all rendered movie tiles.
    """
    return '\n'.join(tile_template.format(movie=movie) for movie in movies)