code: def touch(filename):
      with hl.current_backend().fs.open(filename, "w") as fobj:
          fobj.write("hello world")
  
imports: import json
  import unittest
  import hail
  from hail.utils import *
  from hail.utils.misc import escape_str, escape_id
  from hail.utils.java import FatalError
  from hail.utils.linkedlist import LinkedList
  from ..helpers import *
label_desc: Use image node_id 2 for calling a global function with example usage: touch(filename) without return types