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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 delete_os_dummy_rtr(self, tenant_id, fw_dict, is_fw_virt=False):
 """Delete the Openstack Dummy router and store the info in DB. """

        ret = True
        tenant_name = fw_dict.get('tenant_name')
        try:
            rtr_id = fw_dict.get('router_id')
            if not rtr_id:
                LOG.error("Invalid router id, deleting dummy interface"
                          " failed")
                return False
            if not is_fw_virt:
                ret = self._delete_dummy_intf_rtr(tenant_id, tenant_name,
                                                  rtr_id)
        except Exception as exc:
            # Function _attach_dummy_intf_rtr already took care of
            # cleanup for error cases.
            LOG.error("Deletion of Openstack Router failed tenant "
                      "%(tenant)s, Exception %(exc)s",
                      {'tenant': tenant_id, 'exc': str(exc)})
            ret = False
        if ret:
            res = fw_const.OS_DUMMY_RTR_DEL_SUCCESS
        else:
            res = fw_const.OS_DUMMY_RTR_DEL_FAIL
        self.update_fw_db_result(tenant_id, os_status=res)
        return ret