code: def test_normalize_angle(mean):
      """Testing _normalize_angles() return values between expected bounds"""
      rvs = st.vonmises.rvs(loc=mean, kappa=1, size=1000)
      values = _normalize_angle(rvs, zero_centered=True)
      assert ((-np.pi <= values) & (values <= np.pi)).all()
  
      values = _normalize_angle(rvs, zero_centered=False)
      assert ((values >= 0) & (values <= 2 * np.pi)).all()
  
imports: from unittest.mock import Mock
  import numpy
  import pytest
  import scipy.stats
  from ...data import dict_to_dataset, from_dict, load_arviz_data
  from ...stats.density_utils import _circular_mean, _normalize_angle, _find_hdi_contours
  from ...utils import _stack, _subset_list, _var_names, expand_dims, flatten_inference_data_to_dict, one_de, two_de
  from ..helpers import TestRandomVariable
label_desc: Use image node_id 23 for calling a global function with example usage: test_normalize_angle(mean) without return types