/*
* Lazily Map 7th element and memoise the result
* @param fn Map function
* @return
*/
default <T> PTuple8<T1, T2, T3, T4, T5, T6, T, T8> lazyMap7(Function<T7, T> fn) {
if (arity() != 8) return (PTuple8) PTuple7.super.lazyMap7(fn);
return new LazyMap7PTuple8(fn, (PTuple8) this);
}
