code: def test_key_to_notes(key, ref_notes):
      notes = librosa.key_to_notes(key, unicode=False, natural=True)
      assert len(notes) == len(ref_notes)
      for n, rn in zip(notes, ref_notes):
          assert n == rn
  
imports: import os
  import sys
  import warnings
  import numpy
  import pytest
  import librosa
label_desc: Use image node_id 4 for calling a global function with example usage: test_key_to_notes(key, ref_notes) without return types