fails:Integer#prime_division returns an array of a prime factor and a corresponding exponent
fails:Integer#prime_division returns an empty array for 1
fails:Integer#prime_division returns an empty array for -1
fails:Integer#prime_division raises ZeroDivisionError for 0
fails:"Integer#prime_division returns an array of a prime factor and a corresponding exponent"
fails:"Integer#prime_division returns an empty array for 1"
fails:"Integer#prime_division returns an empty array for -1"
fails:"Integer#prime_division raises ZeroDivisionError for 0"
