@abc.abstractmethod
    def remove_instance(self, usage):
        pass
SubunitReporter.stopTest() sends the subunit 'stopTest' message.
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/compute/resources/base.py/Resource.remove_instance--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/trial/test/test_reporter.py/SubunitReporterTests.test_stopTestSendsSubunitStopTest