private static InternalBuildIdentifier readBuildIdentifier(final IonReader reader, final ReadContext context) {
    IonType ionType = reader.next();
    assertFieldName(reader, "buildIdentifier");
    if (ionType == IonType.NULL || ionType == null) {
      return null;
    }

    reader.stepIn();
    InternalBuildIdentifier buildIdentifier = context.buildsIdentifiersMap
      .computeIfAbsent(readInt(reader, OBJECT_ID_FIELD), new SimpleObjectFactory<InternalBuildIdentifier>() {
        @Override
        public InternalBuildIdentifier create() {
          return new InternalBuildIdentifier(assertNotNull(readFile(reader, "rootDir")));
        }
      });
    reader.stepOut();
    return buildIdentifier;
  }
private static InternalBuildIdentifier readBuildIdentifier(final IonReader reader, final ReadContext context)