beforeCollectorMapping.java

// "Replace 'collect(mapping())' with 'map().collect()'" "true"

import java.util.List;
import java.util.stream.Collectors;

public class Main {
  public List<Integer> sizes(List<String> data) {
    return data.stream().filter(x -> x.startsWith("xyz")).collect(Collectors.mapping(Str<caret>ing::length, Collectors.toList()));
  }
}