code: def demidify(pitches):
      """Transforms MIDI pitches [21,108] to [0, 88)."""
      assertions = [
          tf.assert_greater_equal(pitches, 21),
          tf.assert_less_equal(pitches, 108),
      ]
      with tf.control_dependencies(assertions):
          return pitches - 21
  
file_path: magenta/magenta/models/piano_genie/util.py
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import numpy
  import tensorflow.compat.v1
label_desc: Use image node_id 1 for calling a global function with example usage: demidify(pitches) and returns: unknown