@HiveDecimalWritableVersionV2
  public void setFromDigitsOnlyBytesWithScale(
      boolean isNegative, byte[] bytes, int offset, int length, int scale) {
    fastReset();
    isSet = fastSetFromDigitsOnlyBytesAndScale(isNegative, bytes, offset, length, scale);
    if (!isSet) {
      fastReset();
    }
  }
Set the writable's current value to the decimal digits only in a UTF-8 byte slice, a sign
flag, and a scale.
<p>
Afterwards, the isSet() method will return true, unless byte slice etc could not be converted.
storage-api/src/java/org/apache/hadoop/hive/serde2/io/HiveDecimalWritable.java