alidateAgainst(@NotNull Collection<VFileCreateEvent> childrenToCreate, @NotNull Set<? extends CharSequence> existingNames) {
    childrenToCreate.removeIf(event -> {
      String childName = event.getChildName();
      // assume there is no need to canonicalize names in VFileCreateEvent
      return !myData.isAdoptedName(childName) && existingNames.contains(childName);
    });
  }

  public boo
alidateAgainst(@NotNull Collection<VFileCreateEvent> childrenToCreate, @NotNull Set<? extends CharSequence> existingNames) {
    childre