code: def _test_lines(backend):
      dataset = foz.load_zoo_dataset("quickstart-video")
      view = dataset.filter_labels(
          "frames.detections", F("label") == "vehicle"
      )
  
      plot = fo.lines(
          x="frames.frame_number",
          y=F("frames.detections.detections").length(),
          labels="id",
          samples=view,
          backend=backend,
      )
      plot.show()
  
      input("Press enter to continue...")
  
imports: import random
  import unittest
  import numpy
  import fiftyone
  import fiftyone.brain
  import fiftyone.zoo
  from fiftyone import ViewField
label_desc: Use image node_id 24 for calling a global function with example usage: _test_lines(backend) without return types