code: def convert_yielded(yielded):
      
      # Lists and dicts containing YieldPoints were handled earlier.
      if yielded is None:
          return moment
      elif isinstance(yielded, (list, dict)):
          return multi(yielded)
      elif is_future(yielded):
          return yielded
      elif isawaitable(yielded):
          return _wrap_awaitable(yielded)
      else:
          raise BadYieldError("yielded unknown object %r" % (yielded,))
docs: Convert a yielded object into a `.Future`.
  
      The default implementation accepts lists, dictionaries, and Futures.
  
      If the `~functools.singledispatch` library is available, this function
      may be extended to support additional types. For example::
  
          @convert_yielded.register(asyncio.Future)
          def _(asyncio_future):
              return tornado.platform.asyncio.to_tornado_future(asyncio_future)
  
      .. versionadded:: 4.1