code: def test_cov_trob_3d():
      x = np.array(data[["x", "y", "z"]])
      res = cov_trob(x, cor=True)
  
      # Values from MASS::cov.trob
      n_obs = 5
      center = [2.844500, 3.930879, 3.543190]
      cov = [
          [1.9412275, 2.713547, 0.7242778],
          [2.7135469, 4.479363, 1.2210262],
          [0.7242778, 1.221026, 1.6008466],
      ]
      cor = [
          [1.0000000, 0.9202185, 0.4108583],
          [0.9202185, 1.0000000, 0.4559760],
          [0.4108583, 0.4559760, 1.0000000],
      ]
  
      assert res["n_obs"] == n_obs
      npt.assert_allclose(res["center"], center, rtol=1e-6)
      npt.assert_allclose(res["cov"], cov, rtol=1e-6)
      npt.assert_allclose(res["cor"], cor, rtol=1e-6)
  
imports: import numpy
  import numpy.testing
  import pandas
  from plotnine import aes, geom_point, ggplot, stat_ellipse
  from plotnine.stats.stat_ellipse import cov_trob
label_desc: Use image node_id 3 for calling a global function with example usage: test_cov_trob_3d() without return types