code: def test_psi():
      p = np.array([0.85, 0.05, 0.05, 0.05])
      q = np.array([0.25, 0.25, 0.25, 0.25])
  
      np.testing.assert_almost_equal(
          population_stability_index(p, q), 1.699815077214137, 4
      )
      np.testing.assert_almost_equal(
          population_stability_index(p, q),
          population_stability_index(q, p),
          4,
      )
      np.testing.assert_almost_equal(
          population_stability_index(q, q), 0.0, 4
      )
  
file_path: popmon/tests/popmon/analysis/comparison/test_comparisons.py
imports: import numpy
  import pytest
  from popmon.analysis.comparison.comparisons import jensen_shannon_divergence, ks_prob, ks_test, kullback_leibler_divergence, population_stability_index, uu_chi2
label_desc: Use image node_id 5 for calling a global function with example usage: test_psi() without return types