presto-spi/src/main/java/io/prestosql/spi/type/SqlDecimal.java/SqlDecimal/SqlDecimal
class SqlDecimal:    public SqlDecimal(BigInteger unscaledValue, int precision, int scale)
    {
        this.unscaledValue = unscaledValue;
        this.precision = precision;
        this.scale = scale;
    }