@Nullable
    private static Change findOldChange(@NotNull ObjectOpenHashSet<Change> changesBeforeUpdate, @NotNull Change newChange) {
      Change oldChange = changesBeforeUpdate.get(newChange);
      if (oldChange != null && sameBeforeRevision(oldChange, newChange) &&
          newChange.getFileStatus().equals(oldChange.getFileStatus())) {
        return oldChange;
      }
      return null;
    }
@Nullable
    private static Change findOldChange(@NotNull ObjectOpenHashSet<Change> changesBeforeUpdate, @NotNull Change newChange)