code: def io_storage_usage_bytes(self) -> int:
      if self.io_volume_mount is not None:
          return shutil.disk_usage(self.io_volume_mount).used
      return 0
  
imports: import asyncio
  import errno
  import io
  import logging
  import os
  import shutil
  import struct
  from typing import Optional, Tuple
  import numpy
  import pandas
  from hailtop.aiotools.fs import AsyncFS
  from hailtop.utils import check_shell_output, sleep_before_try, time_msecs, time_ns
label_desc: Use image node_id 11 for calling the ResourceUsageMonitor obj's underlying member method code with example usage: obj.io_storage_usage_bytes() and returns: int, shutil