Remove syntax-formatted lines in the cache. Use this
    when you change the Pygments syntax or Token formatting
    and want to redo how files may have previously been
    syntax marked.

def clear_file_format_cache():
    """Remove syntax-formatted lines in the cache. Use this
    when you change the Pygments syntax or Token formatting
    and want to redo how files may have previously been
    syntax marked."""
    for fname, cache_info in file_cache.items():
        for format, lines in cache_info.lines.items():
            if 'plain' == format: continue
            file_cache[fname].lines[format] = None
            pass
        pass
    pass