public void saveDiffTo(@NotNull DataOutput out,
                         @NotNull DataExternalizer<? super Value> externalizer) throws IOException {
    assert !needsCompacting() : "Full state must be written, instead of diff";

    IntSet set = myInvalidated;
    if (set != null && !set.isEmpty()) {
      for (int inputId : myInvalidated.toIntArray()) {
        DataInputOutputUtil.writeINT(out, -inputId); // mark inputId as invalid, to be processed on load in ValueContainerImpl.readFrom
      }
    }

    final UpdatableValueContainer<Value> toAppend = myAdded;
    if (toAppend != null && toAppend.size() > 0) {
      toAppend.saveTo(out, externalizer);
    }
  }
public void saveDiffTo(@NotNull DataOutput out,
                         @NotNull DataExternalizer<? super Value> externalizer)