// "Replace Stream API chain with loop" "true" import java.util.Arrays; import java.util.List; import java.util.LongSummaryStatistics; public class Main { public static LongSummaryStatistics test(List<List<String>> list) { LongSummaryStatistics stat = new LongSummaryStatistics(); for (List<String> a : list) { if (a != null) { for (String s : a) { long length = s.length(); stat.accept(length); } } } return stat; } public static void main(String[] args) { System.out.println(test(Arrays.asList(null, Arrays.asList("aaa", "b", "cc", "dddd"), Arrays.asList("gggg")))); } }