@property
    def rift_herald_kills(self):
        return self.data.riftHeraldKills
Test that the first strategy is cooperation.
dataset/ETHPy150Open meraki-analytics/cassiopeia/cassiopeia/type/core/match.py/Team.rift_herald_kills--crossover with--dataset/ETHPy150Open Axelrod-Python/Axelrod/axelrod/tests/unit/test_averagecopier.py/TestNiceAverageCopier.test_strategy