Function write_decimal_str 

fn write_decimal_str(f: &mut dyn Write, value_str: &str, scale: i8) -> Result

Writes value_str, the digits of an unscaled decimal value with an optional leading -, to f as a decimal with scale fractional digits: the decimal point is inserted scale digits from the right, with leading zeros as needed, and a negative scale appends zeros instead. The value is always written in full, whatever its precision.