// "Replace Stream API chain with loop" "true" import java.util.List; import java.util.OptionalInt; public class Main { interface Index { int asInteger(); } interface IndexSet<S extends Index> { List<S> asList(); } public static OptionalInt min(IndexSet<?> set) { boolean seen = false; int best = 0; for (Index index : set.asList()) { int asInteger = index.asInteger(); if (!seen || asInteger < best) { seen = true; best = asInteger; } } return seen ? OptionalInt.of(best) : OptionalInt.empty(); } }