code: def pack_zero(file_id, number, length=4):
      number = str(number)
      return file_id + "_" + "0" * (length - len(number)) + number
  
imports: import argparse
  import math
  import os
  import sys
  import music21
  import numpy
  from typeguard import check_argument_types
  from espnet2.fileio.read_text import read_2columns_text
  from espnet2.fileio.score_scp import NOTE, SingingScoreWriter
label_desc: Use image node_id 2 for calling a global function with example usage: pack_zero(file_id, number, length) and returns: unknown