future_test1.py: AttributeError: 'Call' object has no attribute 'ctx'
A `Call.func` does not have a `ctx` if it is invoking the result of another function, i.e. `f(2)(4)`.
```
> python -c 'import ast; print(ast.dump(ast.parse("f(2)(4)")))'
Module(
  body=[Expr(
          value=Call(
                  func=Call(
                         func=Name(
                             id='f',
                             ctx=Load()
                         ),
                         args=[Constant(value=2, kind=None)],
                         keywords=[]
                       ),
                  args=[Constant(value=4, kind=None)],
                  keywords=[]
                )
        )],
  type_ignores=[]
)
```