assert Debug.log("java mirror", Debug.show(symbol) + " -> " + mirror);
assert Debug.log("java mirror: ", symbol, " -> ", mirror);
    public Constructor getConstructor(Symbol symbol) {        Object value = constructors.get(symbol);        if (value != null) return (Constructor)value;        Constructor mirror = getConstructor0(symbol);        assert Debug.log("java mirror", Debug.show(symbol) + " -> " + mirror);        constructors.put(symbol, mirror);        return mirror;    }