@HiveDecimalWritableVersionV1
  public void set(byte[] bigIntegerBytes, int scale) {
    setFromBigIntegerBytesAndScale(bigIntegerBytes, scale);
  }
Set a decimal writable's value from BigInteger bytes and a specified scale.
<p>
If the conversion to decimal is successful, isSet() will return true.
storage-api/src/java/org/apache/hadoop/hive/serde2/io/HiveDecimalWritable.java