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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 update_access_key(self, access_key_id, status, user_name=None):
 """ Changes the status of the specified access key from Active to Inactive or vice versa. This action can be used to disable a user's key as part of a key rotation workflow. If the user_name is not specified, the user_name is determined implicitly based on the AWS Access Key ID used to sign the request. :type access_key_id: string :param access_key_id: The ID of the access key. :type status: string :param status: Either Active or Inactive. :type user_name: string :param user_name: The username of user (optional). """

        params = {'AccessKeyId' : access_key_id,
                  'Status' : status}
        if user_name:
            params['UserName'] = user_name
        return self.get_response('UpdateAccessKey', params)