code: def test_multiple_fields(self):
      dataset = foz.load_zoo_dataset(
          "open-images-v6",
          split="validation",
          label_types=[
              "detections",
              "segmentations",
              "classifications",
          ],
          classes=["Person"],
          max_samples=10,
      ).clone()
  
      prev_dataset = dataset.clone()
  
      anno_key = "anno_key"
      label_schema = {
          "detections": {},
          "segmentations": {"type": "instances"},
          "positive_labels": {},
          "negative_labels": {},
      }
  
      results = dataset.annotate(
          anno_key,
          backend="cvat",
          label_schema=label_schema,
          classes=["Person"],
      )
  
      with results:
          api = results.connect_to_api()
          task_id = results.task_ids[0]
  
          dataset.load_annotations(anno_key, cleanup=True)
  
      def _remove_bbox(dataset, label_field):
          view = dataset.set_field(
              "%s.detections" % label_field,
              F("detections").map(
                  F()
                  .set_field("bounding_box", [])
                  .set_field("mask", None)
              ),
          )
          return view
  
      # Ensure ids and attrs are equal
      view = _remove_bbox(dataset, "detections")
      prev_view = _remove_bbox(prev_dataset, "detections")
      self.assertListEqual(
          view.values("detections", unwind=True),
          prev_view.values("detections", unwind=True),
      )
  
      view = _remove_bbox(dataset, "segmentations")
      prev_view = _remove_bbox(prev_dataset, "segmentations")
      self.assertListEqual(
          view.values("segmentations", unwind=True),
          prev_view.values("segmentations", unwind=True),
      )
  
      self.assertListEqual(
          dataset.values("positive_labels", unwind=True),
          prev_dataset.values("positive_labels", unwind=True),
      )
  
      self.assertListEqual(
          dataset.values("negative_labels", unwind=True),
          prev_dataset.values("negative_labels", unwind=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 3 for calling the CVATTests obj's underlying member method code with example usage: obj.test_multiple_fields() and returns: view