<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _assign_zones(self):
 """Assign all RainCloudyFaucetZone managed by faucet."""

        for zone_id in range(1, 5):
            zone = \
                RainCloudyFaucetZone(
                    parent=self._parent,
                    controller=self._controller,
                    faucet=self,
                    zone_id=zone_id)

            if zone not in self.zones:
                self.zones.append(zone)