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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_instance(self, payload):
 """ Build an instance of AvailableAddOnExtensionInstance :param dict payload: Payload response from the API :returns: twilio.rest.preview.marketplace.available_add_on.available_add_on_extension.AvailableAddOnExtensionInstance :rtype: twilio.rest.preview.marketplace.available_add_on.available_add_on_extension.AvailableAddOnExtensionInstance """

        return AvailableAddOnExtensionInstance(
            self._version,
            payload,
            available_add_on_sid=self._solution['available_add_on_sid'],
        )