new_contents: 
  from django.test import TestCase
  from django.core.exceptions import ValidationError
  from django.db import IntegrityError
  from myhpom.models.health_network import HealthNetwork, PRIORITY
  from myhpom.models.state import State
  
  
  class HealthNetworkModelTestCase(TestCase):
      """
      * with objects.all(), ordering should be by priority, name
      * health networks should be unique for (state, name)
          - can't add the same network name twice for the same state.
          - can add the same network name for two different states.
      * priority must be within [0, 1, 2]
      """
  
      def test_health_networks_ordering(self):
          """ordering of health networks should be by priority, name
          """
          state = State.objects.get(name="NC")
          hns = HealthNetwork.objects.filter(state=state)
          hns_p = {n: [hn for hn in hns if hn.priority == n] for n in PRIORITY.keys()}
          self.assertEqual(
              hns_p[0], hns[: len(hns_p[0])], msg="priority 0 health networks should be first"
          )
          self.assertEqual(
              hns_p[1],
              hns[len(hns_p[0]) : len(hns_p[0]) + len(hns_p[1])],
              msg="priority 1 health networks should be second",
          )
          self.assertEqual(
              hns_p[2],
              hns[len(hns_p[0]) + len(hns_p[1]) : len(hns_p[0]) + len(hns_p[1]) + len(hns_p[2])],
              msg="priority 2 health networks should be third",
          )
  
      def test_unique_health_networks_per_state(self):
          """creating a network with the same name in a different state is fine,
          but creating a network with the same name in the same state raises an IntegrityError
          """
          state1 = State.objects.get(name="NC")
          state2 = State.objects.get(name="SC")
          kwargs = dict(priority=0, name="My Non-existent Health Network")
          hn1 = HealthNetwork.objects.create(state=state1, **kwargs)
          hn2 = HealthNetwork.objects.create(state=state2, **kwargs)
          self.assertRaises(IntegrityError, HealthNetwork.objects.create, state=state2, **kwargs)
  
      def test_add_wrong_priority(self):
          """adding a network with an unsupported priority raises an error
          """
          state = State.objects.get(name="NC")
          bad_priority = len(list(PRIORITY.keys()))   # 1 higher than the available priorities.
          kwargs = dict(state=state, priority=bad_priority, name="My Non-existent Health Network")
          self.assertRaises(ValidationError, HealthNetwork.objects.create, **kwargs)
  
subject: test HealthNetwork model