code: def test_backbones():
      backbones = PointCloudObjectDetector.available_backbones()
      assert backbones == ["pointpillars", "pointpillars_kitti"]
  
imports: import pytest
  from flash.core.utilities.imports import _TOPIC_POINTCLOUD_AVAILABLE
  from flash.pointcloud.detection import PointCloudObjectDetector
  from tests.helpers.task_tester import TaskTester
label_desc: Use image node_id 1 for calling a global function with example usage: test_backbones() without return types