code: function() {
  
        // asech(c) = log((1+sqrt(1-c^2))/c)
  
        var a = this['re'];
        var b = this['im'];
  
        if (this['isZero']()) {
          return Complex['INFINITY'];
        }
  
        var d = a * a + b * b;
        return (d !== 0)
                ? new Complex(
                        a / d,
                        -b / d).acosh()
                : new Complex(
                        (a !== 0) ? a / 0 : 0,
                        (b !== 0) ? -b / 0 : 0).acosh();
      }
docs: Calculate the complex asech
  
  @returns {Complex}