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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 lock(self, key, client):
 """Set the key that will be used to ensure messages come from one party Args: key (string):
 The key used to validate future messages client (string):
 A string that will be returned to indicate who locked this device. """


        self.key = key
        self.client = client