code: def test_save_and_load_empty():
      dense_matrix = np.zeros((4, 6))
      _check_save_and_load(dense_matrix)
  
file_path: scipy/scipy/sparse/tests/test_matrix_io.py
imports: import os
  import numpy
  import tempfile
  from pytest import raises
  from numpy.testing import assert_equal, assert_
  from scipy.sparse import sparray, csc_matrix, csr_matrix, bsr_matrix, dia_matrix, coo_matrix, dok_matrix, csr_array, save_npz, load_npz
label_desc: Use image node_id 4 for calling a global function with example usage: test_save_and_load_empty() without return types