code: def test_list_someempty(self):
      # We want
      #     point_cloud = Pointclouds(
      #         [pcl.points_packed() for pcl in point_clouds],
      #         features=[pcl.features_packed() for pcl in point_clouds],
      #     )
      # to work if point_clouds is a list of pointclouds with some empty and some not.
      points_list = [torch.rand(30, 3), torch.zeros(0, 3)]
      features_list = [torch.rand(30, 3), None]
      pcls = Pointclouds(points=points_list, features=features_list)
      self.assertEqual(len(pcls), 2)
      self.assertClose(
          pcls.points_padded(),
          torch.stack(
              [points_list[0], torch.zeros_like(points_list[0])]
          ),
      )
      self.assertClose(pcls.points_packed(), points_list[0])
      self.assertClose(
          pcls.features_padded(),
          torch.stack(
              [features_list[0], torch.zeros_like(points_list[0])]
          ),
      )
      self.assertClose(pcls.features_packed(), features_list[0])
  
      points_list = [torch.zeros(0, 3), torch.rand(30, 3)]
      features_list = [None, torch.rand(30, 3)]
      pcls = Pointclouds(points=points_list, features=features_list)
      self.assertEqual(len(pcls), 2)
      self.assertClose(
          pcls.points_padded(),
          torch.stack(
              [torch.zeros_like(points_list[1]), points_list[1]]
          ),
      )
      self.assertClose(pcls.points_packed(), points_list[1])
      self.assertClose(
          pcls.features_padded(),
          torch.stack(
              [torch.zeros_like(points_list[1]), features_list[1]]
          ),
      )
      self.assertClose(pcls.features_packed(), features_list[1])
  
imports: import itertools
  import random
  import unittest
  import numpy
  import torch
  from pytorch3d.structures import utils
  from pytorch3d.structures.pointclouds import join_pointclouds_as_batch, join_pointclouds_as_scene, Pointclouds
  from .common_testing import TestCaseMixin
label_desc: Use image node_id 9 for calling the TestPointclouds obj's underlying member method code with example usage: obj.test_list_someempty() without return types