private static ExtendedCell copyToChunkCell(ExtendedCell cell, ByteBuffer buf, int offset,
    int len) {
    int tagsLen = cell.getTagsLength();
    cell.write(buf, offset);
    return createChunkCell(buf, offset, len, tagsLen, cell.getSequenceId());
  }
Clone the passed cell by copying its data into the passed buf and create a cell with a chunkid
out of it
@see #copyBBECToChunkCell(ByteBufferExtendedCell, ByteBuffer, int, int)
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/MemStoreLABImpl.java