code: def test_random(self):
      for _ in range(5):
          vals = torch.randint(size=(20, 2), low=1, high=18)
          sizes = []
          for j in range(vals.shape[0]):
              sizes.append((int(vals[j, 0]), int(vals[j, 1])))
          self.wrap_pack(sizes)
  
imports: import unittest
  import torch
  import torch.nn.functional
  from pytorch3d.renderer.mesh.rasterizer import Fragments
  from pytorch3d.renderer.mesh.textures import _list_to_padded_wrapper, TexturesAtlas, TexturesUV, TexturesVertex
  from pytorch3d.renderer.mesh.utils import pack_rectangles, pack_unique_rectangles, Rectangle
  from pytorch3d.structures import list_to_packed, Meshes, packed_to_list
  from .common_testing import TestCaseMixin
  from .test_meshes import init_mesh
label_desc: Use image node_id 5 for calling the TestRectanglePacking obj's underlying member method code with example usage: obj.test_random() without return types