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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 item(self, key):
 """Retrieves an Item object for the specified key in this bucket. The item need not exist. Args: key: the key of the item within the bucket. Returns: An Item instance representing the specified key. """

    return _item.Item(self._name, key, context=self._context)