code: def test_mean_warning_convergence(mean, get_mats):
      """Test warning for convergence not reached"""
      n_matrices, n_channels = 3, 2
      mats = get_mats(n_matrices, n_channels, "spd")
      with pytest.warns(UserWarning):
          if mean == mean_power:
              mean(mats, 0.3, maxiter=0)
          else:
              mean(mats, maxiter=0)
  
imports: import numpy
  from scipy.stats import gmean
  import pytest
  from pytest import approx
  from pyriemann.utils.geodesic import geodesic_riemann
  from pyriemann.utils.mean import mean_covariance, mean_ale, mean_alm, mean_euclid, mean_harmonic, mean_identity, mean_kullback_sym, mean_logdet, mean_logeuclid, mean_power, mean_riemann, mean_wasserstein, maskedmean_riemann, nanmean_riemann
label_desc: Use image node_id 5 for calling a global function with example usage: test_mean_warning_convergence(mean, get_mats) without return types