code: def test_fps():
      N = 1000
      batch_size = 5
      sample_points = 10
      x = mx.nd.array(
          np.random.uniform(size=(batch_size, int(N / batch_size), 3))
      )
      ctx = F.ctx()
      if F.gpu_ctx():
          x = x.as_in_context(ctx)
      res = farthest_point_sampler(x, sample_points)
      assert res.shape[0] == batch_size
      assert res.shape[1] == sample_points
      assert res.sum() > 0
  
imports: import backend
  import mxnet
  import numpy
  from dgl.geometry import farthest_point_sampler
label_desc: Use image node_id 1 for calling a global function with example usage: test_fps() without return types