<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def release_subnet(self, cidr, direc):
 """Routine to release a subnet from the DB. """

        if direc == 'in':
            self.service_in_ip.release_subnet(cidr)
        else:
            self.service_out_ip.release_subnet(cidr)