text: #!/usr/bin/env python3
  # encoding: utf-8
  
  import contextlib
  
  
  class null_context(contextlib.AbstractContextManager):
  	def __init__(*args, **kwargs):
  		pass
  
  	def __enter__(self):
  		pass
  
  	def __exit__(*args):
  		pass
  
  class async_null_context:
  	def __init__(*args, **kwargs):
  		pass
  
  	async def __aenter__(self):
  		pass
  
  	async def __aexit__(*args):
  		pass
  