override toString of Exception

[David]

class BraLaException : Exception {
     this(string s, string f=__FILE__, size_t l=__LINE__) {
         super(s, f, l);
     }

     override string toString() {
         return "bar";
     }
}


when throwing this exception, I still get the stacktrace and not "bar", 
is it possible to change that behaviour?