code: def test_empty_array_ravel(self, mode):
      res = np.ravel_multi_index(
          np.zeros((3, 0), dtype=np.intp), (2, 1, 0), mode=mode
      )
      assert res.shape == (0,)
  
      with assert_raises(ValueError):
          np.ravel_multi_index(
              np.zeros((3, 1), dtype=np.intp), (2, 1, 0), mode=mode
          )
  
imports: import pytest
  import numpy
  from numpy.testing import assert_, assert_equal, assert_array_equal, assert_almost_equal, assert_array_almost_equal, assert_raises, assert_raises_regex
  from numpy.lib._index_tricks_impl import mgrid, ogrid, ndenumerate, fill_diagonal, diag_indices, diag_indices_from, index_exp, ndindex, c_, r_, s_, ix_
label_desc: Use image node_id 8 for calling the TestRavelUnravelIndex obj's underlying member method code with example usage: obj.test_empty_array_ravel(mode) without return types