code: def test_deleted_label_field(self):
      dataset = foz.load_zoo_dataset(
          "quickstart", max_samples=1
      ).clone()
      view = dataset.select_fields("ground_truth")
      prev_ids = dataset.values(
          "ground_truth.detections.id", unwind=True
      )
  
      anno_key = "anno_key"
      results = view.annotate(
          anno_key,
          backend="cvat",
          label_field="ground_truth",
      )
      dataset.delete_sample_field("ground_truth")
      dataset.reload()
  
      dataset.load_annotations(anno_key, cleanup=True)
      self.assertListEqual(
          sorted(
              dataset.values("ground_truth.detections.id", unwind=True)
          ),
          sorted(prev_ids),
      )
  
      # Test scalar
      view = dataset.select_fields("uniqueness")
      anno_key = "anno_key2"
      results = view.annotate(
          anno_key,
          backend="cvat",
          label_field="uniqueness",
      )
      dataset.delete_sample_field("uniqueness")
      dataset.reload()
  
      dataset.load_annotations(anno_key, cleanup=True)
  
imports: from bson import ObjectId
  from collections import defaultdict
  import numpy
  import os
  import unittest
  import eta.core.utils
  import fiftyone
  import fiftyone.utils.cvat
  import fiftyone.zoo
  from fiftyone.core.expressions import ViewField
label_desc: Use image node_id 17 for calling the CVATTests obj's underlying member method code with example usage: obj.test_deleted_label_field() without return types