code: def touch(fs, filename: str):
      with fs.open(filename, "w") as fobj:
          fobj.write("hello world")
  
imports: from typing import Generator
  import pytest
  import secrets
  import os
  import hail
  import hailtop.fs
  from hail.context import _get_local_tmpdir
  from hail.utils import hadoop_open, hadoop_copy, hadoop_ls
  from hailtop.utils import secret_alnum_string
  from hail.utils.java import FatalError
  from ..helpers import qobtest
label_desc: Use image node_id 1 for calling a global function with example usage: touch(fs, filename) without return types