@gen.coroutine
    def authenticate(self, handler, data):
Asserts that val is a unicode string.
dataset/ETHPy150Open jupyterhub/jupyterhub/jupyterhub/auth.py/Authenticator.authenticate--crossover with--dataset/ETHPy150Open ActivisionGameScience/assertpy/assertpy/assertpy.py/AssertionBuilder.is_unicode