code: def test_reduce_dims():
      matrix = np.random.rand(100, 100)
      assert reduce_dims(matrix, 50).shape[1] == 50
  
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 4 for calling a global function with example usage: test_reduce_dims() without return types