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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 only(self, *keys):
 """ Get the items with the specified keys. :param keys: The keys to keep :type keys: tuple :rtype: Collection """

        items = []

        for key, value in enumerate(self.items):
            if key in keys:
                items.append(value)

        return self.__class__(items)