How to get the UDAs for a function parameter correctly?

[Heromyth via Digitalmars-d-learn]

I want to get the UDAs for for a function parameter. Here the 
test code and I got some errors:

source/app.d(29,33): Error: first argument is not a symbol
source/app.d(39,15): Error: template instance app.test!(ClassA) 
error instantiating

How can I fix this? Would this be a bug? Thanks.

=====================
import std.stdio;
import std.traits;
import std.meta;


struct Length {
    int a;
    int b;
}

class ClassA {
    void test(@Length(1, 9) int len, @Length(2, 4) int size) {
        writeln("It's OK");
    }

    void test(string name) {
        writeln("Can't be compiled");
    }
}

string test(T)() {
    string str;
    alias currentMembers = __traits(getOverloads, T, "test");

    static foreach(member; currentMembers) {{
        alias Params = Parameters!(member);
        static foreach(i; 0 .. Params.length)
        {{
            alias ThisParameter =  Params[i .. i + 1];
            static foreach(uda; __traits(getAttributes, 
ThisParameter)) {
                str ~= uda.stringof ~  "\n";
            }
        }}
    }}

    return str;
}

void main() {
    enum aa = test!(ClassA);
    writeln(aa);
}