code: def check(fn):
      """Decorator to register a function as a check.
  
      Checks are run in the order in which they are registered.
  
      Args:
        fn: A function that takes no arguments and either returns `None` or
          returns a generator of `Suggestion`s. (The ability to return
          `None` is to work around the awkwardness of defining empty
          generator functions in Python.)
  
      Returns:
        A wrapped version of `fn` that returns a generator of `Suggestion`s.
      """
  
      @functools.wraps(fn)
      def wrapper():
          result = fn()
          return iter(()) if result is None else result
  
      CHECKS.append(wrapper)
      return wrapper
  
imports: import dataclasses
  import errno
  import functools
  import hashlib
  import inspect
  import logging
  import os
  import pipes
  import shlex
  import socket
  import subprocess
  import sys
  import tempfile
  import textwrap
  import traceback
label_desc: Use image node_id 1 for calling a global function with example usage: check(fn) and returns: wrapper, unknown