public static int getMobValueLength(Cell cell) {
    return PrivateCellUtil.getValueAsInt(cell);
  }
Gets the mob value length from the mob ref cell. A mob ref cell has a mob reference tag. The
value of a mob ref cell consists of two parts, real mob value length and mob file name. The
real mob value length takes 4 bytes. The remaining part is the mob file name.
@param cell The mob ref cell.
@return The real mob value length.
hbase-server/src/main/java/org/apache/hadoop/hbase/mob/MobUtils.java