protected @NotNull ParsedChanges parseChanges() {
      List<Change> mergedChanges = parseMergedChanges();
      List<Collection<Change>> changes = computeChanges(mergedChanges);
      ParsedChanges parsedChanges = new ParsedChanges(mergedChanges, changes);
      myChanges.compareAndSet(this, parsedChanges);
      return parsedChanges;
    }
protected @NotNull ParsedChanges parseChanges()