'Fetch a AvailableAddOnExtensionInstance
:returns: Fetched AvailableAddOnExtensionInstance
:rtype: twilio.rest.preview.marketplace.available_add_on.available_add_on_extension.AvailableAddOnExtensionInstance'

def fetch(self):

    params = values.of({})
    payload = self._version.fetch('GET', self._uri, params=params)
    return AvailableAddOnExtensionInstance(self._version, payload, available_add_on_sid=self._solution['available_add_on_sid'], sid=self._solution['sid'])
