def extensions(self):
        """
        Access the extensions

        :returns: twilio.rest.api.v2010.account.incoming_phone_number.assigned_add_on.assigned_add_on_extension.AssignedAddOnExtensionList
        :rtype: twilio.rest.api.v2010.account.incoming_phone_number.assigned_add_on.assigned_add_on_extension.AssignedAddOnExtensionList
        """
        if self._extensions is None:
            self._extensions = AssignedAddOnExtensionList(
                self._version,
                account_sid=self._solution['account_sid'],
                resource_sid=self._solution['resource_sid'],
                assigned_add_on_sid=self._solution['sid'],
            )
        return self._extensions
Access the extensions

        :returns: twilio.rest.api.v2010.account.incoming_phone_number.assigned_add_on.assigned_add_on_extension.AssignedAddOnExtensionList
        :rtype: twilio.rest.api.v2010.account.incoming_phone_number.assigned_add_on.assigned_add_on_extension.AssignedAddOnExtensionList