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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 booleanise(b):
 """Normalise a 'stringified' Boolean to a proper Python Boolean. ElasticSearch has a habit of returning "true" and "false" in its JSON responses when it should be returning `true` and `false`. If `b` looks like a stringified Boolean true, return True. If `b` looks like a stringified Boolean false, return False. If we don't know what `b` is supposed to represent, return it back to the caller. """

    s = str(b)
    if s.lower() == "true":
        return True
    if s.lower() == "false":
        return False

    return b