code: def test_load_tempo_from_file(self):
      annotations = load_tempo(pj(ANNOTATIONS_PATH, "sample.tempo"))
      self.assertIsInstance(annotations, np.ndarray)
  
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 1 for calling the TestLoadTempoFunction obj's underlying member method code with example usage: obj.test_load_tempo_from_file() without return types