Consider the following function, which we'd like to not be constant on integers `a`, but which always returns `(1,2)`:

```
def foo(a):
    b = 1
    c = 2
    def bar(b,c):
        b = b + a
        c = c + a
    bar(b,c)
    return (b,c)

```

If I understand correctly, the idiomatic way to implement `bar(b,c)` would be to give it no parameters at all and declare b and c nonlocal inside its definition. I'm curious, however: how do we make an inner function have nonlocal effects on its parameters?