As it happens, I tried that before my second answer.
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.
In [1]: import tornado
In [2]: from tornado.log import gen_log
In [3]: from tornado import ioloop
In [4]: ioloop.IOLoop
Out[4]: tornado.ioloop.IOLoop
In [5]: if not hasattr(ioloop.IOLoop, 'configurable_default'):
...: raise ImportError("Tornado too old: %s" % getattr(tornado, 'version', 'unknown'))
...:
In [6]: getattr(tornado, 'version', 'unknown')
Out[6]: '6.0.4'
In [7]: getattr(ioloop.IOLoop,'configurable_default')
Out[7]: <bound method IOLoop.configurable_default of <class 'tornado.ioloop.IOLoop'>>
So nothing to see here.