code: def test_empty_input(self):
      example = TensorPropertiesTestClass(x=(), y=())
      self.assertTrue(len(example) == 0)
      self.assertTrue(example.isempty())
  
imports: import unittest
  import numpy
  import torch
  from pytorch3d.common.compat import meshgrid_ij
  from pytorch3d.ops import eyes
  from pytorch3d.renderer import AlphaCompositor, PerspectiveCameras, PointsRasterizationSettings, PointsRasterizer, PointsRenderer
  from pytorch3d.renderer.utils import ndc_grid_sample, ndc_to_grid_sample_coords, TensorProperties
  from pytorch3d.structures import Pointclouds
  from .common_testing import TestCaseMixin
label_desc: Use image node_id 5 for calling the TestTensorProperties obj's underlying member method code with example usage: obj.test_empty_input() without return types