code: def test_dtw_nan_fail():
      C = np.ones((10, 10))
      C[4, 6] = np.nan
      librosa.sequence.dtw(C=C)
  
imports: import librosa
  import numpy
  from scipy.spatial.distance import cdist
  import pytest
  from test_core import srand
label_desc: Use image node_id 23 for calling a global function with example usage: test_dtw_nan_fail() without return types