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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 default_kms_key_name(self, value):
 """Set default KMS encryption key for objects in the bucket. :type value: str or None :param value: new KMS key name (None to clear any existing key). """

        encryption_config = self._properties.get("encryption", {})
        encryption_config["defaultKmsKeyName"] = value
        self._patch_property("encryption", encryption_config)