def evaluate(self, _tuple, scheme, state=None):
        return self.input.evaluate(None, None, state)
A resource that is always called 'bar' but is created per-request
dataset/ETHPy150Open uwescience/raco/raco/expression/aggregate.py/UdaAggregateExpression.evaluate--crossover with--dataset/ETHPy150Open twisted/nevow/examples/children/children.py/RootPage.child_bar