@cache_readonly
    def _max_groupsize(self):
        # For many items in each group this is much faster than
        # self.size().max(), in worst case marginally slower
        if self.indices:
            return max(len(v) for v in self.indices.values())
        else:
            return 0
Returns a global `IOLoop` instance.
dataset/ETHPy150Open pydata/pandas/pandas/core/groupby.py/BaseGrouper._max_groupsize--crossover with--dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/ioloop.py/IOLoop.instance