Function compose4 

pub fn compose4<A, B, C, D, E, F1, F2, F3, F4>(
    f: F1,
    g: F2,
    h: F3,
    i: F4,
) -> impl Fn(A) -> E
where
    F1: Fn(D) -> E,
    F2: Fn(C) -> D,
    F3: Fn(B) -> C,
    F4: Fn(A) -> B,