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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 set(self, key, func, *args, **kwargs):
 """Return key's value if it exists, otherwise call given function. :param key: The key to lookup/set. :param func: A function to use if the key doesn't exist. All other arguments and keyword arguments are passed to *func*. """

        if key in self:
            return self[key]
        self[key] = value = func(*args, **kwargs)
        return value