@Override
  public boolean equals(Object obj) {
    if (obj == null) {
      return false;
    }
    if (obj == this) {
      return true;
    }
    if (obj instanceof Size) {
      return compareTo((Size) obj) == 0;
    }
    return false;
  }
get the value which is converted to specified unit.
@param unit size unit
@return the converted value
hbase-client/src/main/java/org/apache/hadoop/hbase/Size.java