def on_userType(self, node):
        yield '_'.join(self.visit(*node.children))
listdir.
dataset/ETHPy150Open Evgenus/protocyt/protocyt/compiler.py/CodeGenerator.on_userType--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/files/file_service_stub.py/GoogleStorage.listdir