/**
* Lazily Map 1st element and memoise the result
*
* @param fn Map function
* @return
*/
default <T> PTuple8<T, T2, T3, T4, T5, T6, T7, T8> lazyMap1(Function<T1, T> fn) {
if (arity() != 8) return (PTuple8) PTuple7.super.lazyMap1(fn);
return new LazyMap1PTuple8(fn, this);
}
