code: def test_van_der_corput():
      sample = sequences.van_der_corput(10)
      out = [
          0.0,
          0.5,
          0.25,
          0.75,
          0.125,
          0.625,
          0.375,
          0.875,
          0.0625,
          0.5625,
      ]
      npt.assert_almost_equal(sample, out)
  
      sample = sequences.van_der_corput(5, start_index=3)
      out = [0.75, 0.125, 0.625, 0.375, 0.875]
      npt.assert_almost_equal(sample, out)
  
imports: import numpy
  import numpy.testing
  from statsmodels.tools import sequences
label_desc: Use image node_id 2 for calling a global function with example usage: test_van_der_corput() without return types