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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 get_translated_items(fapi, file_uri, use_cache, cache_dir=None):
 """ Returns the last modified from smarterling """

    items = None
    cache_file = os.path.join(cache_dir, sha1(file_uri)) if use_cache else None
    if use_cache and os.path.exists(cache_file):
        print("Using cache file %s for translated items for: %s" % (cache_file, file_uri))
        items = json.loads(read_from_file(cache_file))
    if not items:
        print("Downloading %s from smartling" % file_uri)
        (response, code) = fapi.last_modified(file_uri)
        items = response.data.items
        if cache_file:
            print("Caching %s to %s" % (file_uri, cache_file))
            write_to_file(cache_file, json.dumps(items))
    return items