// "Replace loop with 'List.replaceAll()'" "true"
import java.util.List;

class Main {
  void modifyStrings(List<String> strings) {
    for<caret> (int i = 0; i < strings.size(); i++) {
      String replacement = strings.get(i) + strings.get(i);
      strings.set(i, replacement);
    }
  }
}