edits2.java

private List<String> edits2(String typo) {
  // Repeatedly apply all 4 edits twice, and in parallel, to each split.
  // Packing removes duplicates, ensures result presence in dictionary and
  // orders by rank
  return
    pack(edits1(typo).parallelStream()
      .flatMap(w -> edits1(w).stream()));
}