DecimalFraction

The element following this tag is an array that contains exactly two integer numbers:

1. Exponent e with base 10 (must be Int or Long, i.e. BigNum is disallowed)
2. Mantissa m (Int, Long or BigNum) The value of the decimal fraction is m*(10**e).

NOTE: This tag isn't actually ever produced by the CBOR parser, since it has built-in support for it and immediately produces a java.math.BigDecimal instead.