@cassiopeia.type.core.common.lazyproperty
    def masteries(self):
        masteries = []
        ranks = []
        for mastery in self.data.participant.masteries:
            masteries.append(mastery.masteryId)
            ranks.append(mastery.rank)
        return dict(zip(cassiopeia.riotapi.get_masteries(masteries), ranks))
Installs a start_new_thread replacement created by _MakeStartNewThread.
dataset/ETHPy150Open meraki-analytics/cassiopeia/cassiopeia/type/core/match.py/Participant.masteries--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/runtime/runtime.py/PatchStartNewThread