code: def test_sqrtm():
      """Test matrix square root"""
      C = 2 * np.eye(n_channels)
      Ctrue = np.sqrt(2) * np.eye(n_channels)
      assert_array_almost_equal(sqrtm(C), Ctrue, decimal=10)
  
      C = np.array([[1, -1j], [1j, 1]])
      Ctrue = np.sqrt(2) / 2 * C
      assert_array_almost_equal(sqrtm(C), Ctrue, decimal=10)
  
file_path: pyRiemann/tests/test_utils_base.py
imports: import pytest
  import numpy
  from numpy.testing import assert_array_almost_equal
  from pyriemann.utils.base import expm, invsqrtm, logm, powm, sqrtm, nearest_sym_pos_def
  from pyriemann.utils.mean import mean_riemann
  from pyriemann.utils.test import is_pos_def, is_sym_pos_def
label_desc: Use image node_id 5 for calling a global function with example usage: test_sqrtm() without return types