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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 map_names(lang="en"):
 """This resource returns an dictionary of the localized map names for the specified language. Only maps with events are listed - if you need a list of all maps, use ``maps.json`` instead. :param lang: The language to query the names for. :return: the response is a dictionary where the key is the map id and the value is the name of the map in the specified language. """

    cache_name = "map_names.%s.json" % lang
    data = get_cached("map_names.json", cache_name, params=dict(lang=lang))
    return dict([(item["id"], item["name"]) for item in data])