pipe2<A, B>  function 
 
- A a,
- B ab(- A
 
Transforms the input a by applying the function ab.
Implementation
B pipe2<A, B>(A a, B Function(A) ab) {
  return ab(a);
}Transforms the input a by applying the function ab.
B pipe2<A, B>(A a, B Function(A) ab) {
  return ab(a);
}