code: def test_simple(self):
      num_points = 2048
      pos = torch.randn((num_points, 3)).cuda()
      batch = torch.zeros((num_points)).cuda().long()
      idx = fps(pos, batch, 0.25)
  
      idx = idx.detach().cpu().numpy()
  
      cnd_1 = np.sum(idx) > 0
      cnd_2 = np.sum(idx) < num_points * idx.shape[0]
  
      assert (
          cnd_1 and cnd_2
      ), "Your Pytorch Cluster FPS doesn't seem to return the correct value. It shouldn't be used to perform sampling"
  
file_path: torch-points3d/test/test_fps.py
imports: import torch
  import numpy
  from torch_geometric.nn import fps
  import unittest
  import logging
  import os
  import sys
  from test import run_if_cuda
  from torch_points3d.datasets.registration.utils import fps_sampling
label_desc: Use image node_id 1 for calling the TestPytorchClusterFPS obj's underlying member method code with example usage: obj.test_simple() without return types