code: def test_load_timestamps_only(self):
      events = load_onsets(pj(ANNOTATIONS_PATH, "stereo_sample.notes"))
      self.assertTrue(
          np.allclose(
              events,
              [0.147, 1.567, 2.526, 2.549, 2.563, 2.577, 3.369, 3.449],
          )
      )
  
imports: from __future__ import absolute_import, division, print_function
  import unittest
  from os.path import join, join
  from madmom.io import *
  from madmom.io import load_beats, load_key, load_notes, load_onsets, load_tempo
  from tests import ANNOTATIONS_PATH, DETECTIONS_PATH
  from .None import DATA_PATH
label_desc: Use image node_id 4 for calling the TestLoadOnsetsFunction obj's underlying member method code with example usage: obj.test_load_timestamps_only() without return types