def __getitem__(self, fileobj):
        try:
            fd = self._selector._fileobj_lookup(fileobj)
            return self._selector._fd_to_key[fd]
        except __HOLE__:
            raise KeyError("{0!r} is not registered".format(fileobj))
dataset/ETHPy150Open dpkp/kafka-python/kafka/selectors34.py/_SelectorMapping.__getitem__