@Override
  public ByteBuffer readBinary() throws TException {
    int size = readI32();
    if (lastPrimitiveWasNull) {
      return null;
    }
    byte[] buf = new byte[size];
    readRawAll(buf, 0, size);
    return ByteBuffer.wrap(buf);
  }
This method always return the same instance of TSet to avoid creating new
instances. It is the responsibility of the caller to read the value before
calling this method again.
serde/src/java/org/apache/hadoop/hive/serde2/thrift/TBinarySortableProtocol.java