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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 get_config(self, key, default=MISSING):
 """Get the value of a persistent config key from the registry If no default is specified and the key is not found ArgumentError is raised. Args: key (string):
 The key name to fetch default (string):
 an optional value to be returned if key cannot be found Returns: string: the key's value """


        keyname = "config:" + key

        try:
            return self.kvstore.get(keyname)
        except KeyError:
            if default is MISSING:
                raise ArgumentError("No config value found for key", key=key)

            return default