code: def convert_musicxml(root_dir, sub_dir, full_file_path):
      """Converts a musicxml file to a sequence proto.
  
      Args:
        root_dir: A string specifying the root directory for the files being
            converted.
        sub_dir: The directory being converted currently.
        full_file_path: the full path to the file to convert.
  
      Returns:
        Either a NoteSequence proto or None if the file could not be converted.
      """
      try:
          sequence = musicxml_reader.musicxml_file_to_sequence_proto(
              full_file_path
          )
      except musicxml_reader.MusicXMLConversionError as e:
          tf.logging.warning(
              "Could not parse MusicXML file %s. It will be skipped. Error was: %s",
              full_file_path,
              e,
          )
          return None
      sequence.collection_name = os.path.basename(root_dir)
      sequence.filename = os.path.join(
          sub_dir, os.path.basename(full_file_path)
      )
      sequence.id = generate_note_sequence_id(
          sequence.filename, sequence.collection_name, "musicxml"
      )
      tf.logging.info("Converted MusicXML file %s.", full_file_path)
      return sequence
  
file_path: magenta/magenta/scripts/convert_dir_to_note_sequences.py
imports: import hashlib
  import os
  from note_seq import abc_parser
  from note_seq import midi_io
  from note_seq import musicxml_reader
  import tensorflow.compat.v1
label_desc: Use image node_id 4 for calling a global function with example usage: convert_musicxml(root_dir, sub_dir, full_file_path) and returns: sequence, None