public void initialize(UnreadPdxType unreadType, PdxReaderImpl reader) {
    this.unreadType = unreadType;
    int[] indexes = unreadType.getUnreadFieldIndexes();
    unreadData = new byte[indexes.length][];
    int i = 0;
    for (int idx : indexes) {

      ByteSource field = reader.getRaw(idx);

      // Copy the unread data into a new byte array
      unreadData[i] = new byte[field.capacity()];
      field.position(0);
      field.get(unreadData[i]);
      i++;
    }
  }
This is the original type of the blob that we deserialized and did not read some of its fields.
geode-core/src/main/java/org/apache/geode/pdx/internal/PdxUnreadData.java