docs: def assert_corofunction(**kw):
      """
      Asserts if a given values are a coroutine function.
  
      Arguments:
          **kw (mixed): value to check if it is an iterable.
  
      Raises:
          TypeError: if assertion fails.
      """
      for name, value in kw.items():
          if not asyncio.iscoroutinefunction(value):
              raise TypeError(
                  'paco: {} must be a coroutine function'.format(name))