@Override
    public ByteBuffer next() {
      if (curItemIndex >= items.length) {
        throw new NoSuchElementException("items overflow");
      }
      curItem = items[curItemIndex++];
      return curItem;
    }
Provides a unified view of all the underlying ByteBuffers and will look as if a bigger sequential
buffer. This class provides similar APIs as in {@link ByteBuffer} to put/get int, short, long etc
and doing operations like mark, reset, slice etc. This has to be used when data is split across
multiple byte buffers and we don't want copy them to single buffer for reading from it.
hbase-common/src/main/java/org/apache/hadoop/hbase/nio/MultiByteBuff.java