code: def test_video_dataset_frames_init(self):
      dataset = fo.Dataset()
      conn = foo.get_db_conn()
  
      collections = conn.list_collection_names()
      self.assertIn(dataset._sample_collection_name, collections)
  
      self.assertIsNone(dataset._frame_collection)
      self.assertIsNone(dataset._frame_collection_name)
      self.assertTrue(len(dataset._doc.frame_fields) == 0)
  
      dataset.media_type = "video"
  
      self.assertIsNotNone(dataset._frame_collection)
      self.assertIsNotNone(dataset._frame_collection_name)
      self.assertTrue(len(dataset._doc.frame_fields) > 0)
  
      collections = conn.list_collection_names()
      self.assertIn(dataset._frame_collection_name, collections)
  
imports: from copy import deepcopy
  from datetime import date, datetime
  from bson import ObjectId
  import numpy
  import unittest
  import fiftyone
  import fiftyone.core.odm
  from fiftyone import ViewField
  from decorators import drop_datasets
label_desc: Use image node_id 2 for calling the VideoTests obj's underlying member method code with example usage: obj.test_video_dataset_frames_init() without return types