def outer19(x):
            """ closure as arg to another closure """
            z1 = x + 1
            z2 = x + 2

            def inner(x):
                return x + z1

            def inner2(f, x):
                return f(x) + z2

            return inner2(inner, x)
 closure as arg to another closure 
numba/tests/test_closure.py