code: function(m) {
  
        if (m < 0) {
          return new Fraction(Math.pow(this['s'] * this["d"], -m), Math.pow(this["n"], -m));
        } else {
          return new Fraction(Math.pow(this['s'] * this["n"], m), Math.pow(this["d"], m));
        }
      }
docs: Calculates the fraction to some integer exponent
  
  Ex: new Fraction(-1,2).pow(-3) => -8