code: def _swap_current_task(loop, task):
      prev_task = _current_tasks.get(loop)
      if task is None:
          del _current_tasks[loop]
      else:
          _current_tasks[loop] = task
      return prev_task
  
imports: import concurrent.futures
  import contextvars
  import functools
  import inspect
  import itertools
  import math
  import types
  import weakref
  from types import GenericAlias
  from .None import base_tasks
  from .None import coroutines
  from .None import events
  from .None import exceptions
  from .None import futures
  from .None import timeouts
label_desc: Use image node_id 16 for calling a global function with example usage: _swap_current_task(loop, task) and returns: prev_task