code: def test_knn_cuda(algorithm, dist, exclude_self):
      if not th.cuda.is_available():
          return
      _test_knn_common(F.cuda(), algorithm, dist, exclude_self)
  
file_path: dgl/tests/python/pytorch/geometry/test_geometry.py
imports: import backend
  import dgl
  import dgl.nn
  import numpy
  import pytest
  import torch
  from dgl import DGLError
  from dgl.base import DGLWarning
  from dgl.geometry import farthest_point_sampler, neighbor_matching
  from utils import parametrize_idtype
  from utils.graph_cases import get_cases
label_desc: Use image node_id 5 for calling a global function with example usage: test_knn_cuda(algorithm, dist, exclude_) without return types