content: from django.test import TestCase
  from django.db.backends.postgresql.psycopg_any import NumericRange
  from ipam.models import VLANGroup
  
  
  class VLANGroupRangeContainsLookupTests(TestCase):
      @classmethod
      def setUpTestData(cls):
          # Two ranges: [1,11) and [20,31)
          cls.g1 = VLANGroup.objects.create(
              name='VlanGroup-A',
              slug='VlanGroup-A',
              vid_ranges=[NumericRange(1, 11), NumericRange(20, 31)],
          )
          # One range: [100,201)
          cls.g2 = VLANGroup.objects.create(
              name='VlanGroup-B',
              slug='VlanGroup-B',
              vid_ranges=[NumericRange(100, 201)],
          )
          cls.g_empty = VLANGroup.objects.create(
              name='VlanGroup-empty',
              slug='VlanGroup-empty',
              vid_ranges=[],
          )
  
      def test_contains_value_in_first_range(self):
          """
          Tests whether a specific value is contained within the first range in a queried
          set of VLANGroup objects.
          """
          names = list(
              VLANGroup.objects.filter(vid_ranges__range_contains=10).values_list('name', flat=True).order_by('name')
          )
          self.assertEqual(names, ['VlanGroup-A'])
  
      def test_contains_value_in_second_range(self):
          """
          Tests if a value exists in the second range of VLANGroup objects and
          validates the result against the expected list of names.
          """
          names = list(
              VLANGroup.objects.filter(vid_ranges__range_contains=25).values_list('name', flat=True).order_by('name')
          )
          self.assertEqual(names, ['VlanGroup-A'])
  
      def test_upper_bound_is_exclusive(self):
          """
          Tests if the upper bound of the range is exclusive in the filter method.
          """
          # 11 is NOT in [1,11)
          self.assertFalse(VLANGroup.objects.filter(vid_ranges__range_contains=11).exists())
  
      def test_no_match_far_outside(self):
          """
          Tests that no VLANGroup contains a VID within a specified range far outside
          common VID bounds and returns `False`.
          """
          self.assertFalse(VLANGroup.objects.filter(vid_ranges__range_contains=4095).exists())
  
      def test_empty_array_never_matches(self):
          """
          Tests the behavior of VLANGroup objects when an empty array is used to match a
          specific condition.
          """
          self.assertFalse(VLANGroup.objects.filter(pk=self.g_empty.pk, vid_ranges__range_contains=1).exists())
  