@HiveDecimalWritableVersionV1
  public HiveDecimal getHiveDecimal(int maxPrecision, int maxScale) {
    if (!isSet) {
      return null;
    }
    HiveDecimal dec = HiveDecimal.createFromFast(this);
    HiveDecimal result = HiveDecimal.enforcePrecisionScale(dec, maxPrecision, maxScale);
    return result;
  }
Get a HiveDecimal instance from the writable and constraint it with maximum precision/scale.
<p>
@param maxPrecision maximum precision
@param maxScale maximum scale
@return HiveDecimal instance
storage-api/src/java/org/apache/hadoop/hive/serde2/io/HiveDecimalWritable.java