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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def simple_parse_file(filename: str) -> Feed: """Parse an Atom, RSS or JSON feed from a local file."""

    pairs = (
        (rss.parse_rss_file, _adapt_rss_channel),
        (atom.parse_atom_file, _adapt_atom_feed),
        (json_feed.parse_json_feed_file, _adapt_json_feed)
    )
    return _simple_parse(pairs, filename)