@tornado.gen.coroutine
    def delprop(self, ctx, loctx, key):
        if ctx.level != LEVEL_EXECUTE:
            raise Exception('Properties may only be deleted in action code (player prop "%s")' % (key,))
        iid = loctx.iid
        uid = self.uid
        app = ctx.app
        
        tup = ('iplayerprop', iid, uid, key)
        yield app.propcache.delete(tup)
        ctx.task.changeset.add(tup)
A test method which runs and has an error recorded against it is
dataset/ETHPy150Open erkyrath/tworld/lib/two/execute.py/PlayerProxy.delprop--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/trial/test/test_reporter.py/ErrorReportingTests.test_formatErroredMethod