code: def test_build_slot_sharing_group_with_unknown_resource(self):
      name = "slot_sharing_group"
      slot_sharing_group = SlotSharingGroup.builder(name).build()
      self.assertEqual(slot_sharing_group.get_name(), name)
      self.assertIsNone(slot_sharing_group.get_cpu_cores())
      self.assertIsNone(slot_sharing_group.get_task_heap_memory())
      self.assertIsNone(slot_sharing_group.get_task_off_heap_memory())
      self.assertIsNone(slot_sharing_group.get_managed_memory())
      self.assertEqual(slot_sharing_group.get_external_resources(), {})
  
imports: from pyflink.datastream.slot_sharing_group import MemorySize, SlotSharingGroup
  from pyflink.testing.test_case_utils import PyFlinkTestCase
label_desc: Use image node_id 2 for calling the SlotSharingGroupTests obj's underlying member method code with example usage: obj.test_build_slot_sharing_group_with_unknown_resource() without return types