code: def test_mean_center(matrix):
      mean_center(matrix)
      assert np.allclose(
          np.mean(matrix, axis=0),
          np.zeros(matrix.shape[1], dtype="float64"),
          atol=1e-10,
      )
  
file_path: recommenders/tests/unit/recommenders/models/test_geoimc.py
imports: import collections
  import pytest
  import numpy
  from scipy.sparse import csr_matrix
label_desc: Use image node_id 3 for calling a global function with example usage: test_mean_center(matrix) without return types