@Override
  public void get(byte[] dst, int offset, int length) {
    checkRefCount();
    while (length > 0) {
      int toRead = Math.min(length, this.curItem.remaining());
      ByteBufferUtils.copyFromBufferToArray(dst, this.curItem, this.curItem.position(), offset,
        toRead);
      this.curItem.position(this.curItem.position() + toRead);
      length -= toRead;
      if (length == 0) break;
      this.curItemIndex++;
      this.curItem = this.items[this.curItemIndex];
      offset += toRead;
    }
  }
Copies the specified number of bytes from this MBB's current position to the byte[]'s offset.
Also advances the position of the MBB by the given length.
hbase-common/src/main/java/org/apache/hadoop/hbase/nio/MultiByteBuff.java