code: def test_load_numpy2d_multivariate_raises(loader):
      """Test that multivariate and/or unequal length raise the correct error."""
      with pytest.raises(
          ValueError, match="attempting to load into a numpy2d"
      ):
          X, y = loader(return_type="numpy2d")
  
imports: import numpy
  import pandas
  import pytest
  from sktime.datasets import load_acsf1, load_arrow_head, load_basic_motions, load_italy_power_demand, load_japanese_vowels, load_osuleaf, load_plaid, load_tecator, load_unit_test
label_desc: Use image node_id 4 for calling a global function with example usage: test_load_numpy2d_multivariate_raises(loader) without return types