How decode encoded Base64 to string text?

[Marcone via Digitalmars-d-learn]

I can encode "Helo World!" to Base64 and get "TWFyY29uZQ==", but 
if I try to decode "TWFyY29uZQ==" I can not recovery "Helo 
World!" but [77, 97, 114, 99, 111, 110, 101]. How can I recover 
"Helo World!" when decode? Thank you.

import std;

void main(){
        string text = "Helo World!";

        auto encoded = Base64.encode(text.representation);
        auto decoded = Base64URL.decode("TWFyY29uZQ==");

        writeln(encoded); // prints: "TWFyY29uZQ=="
	writeln(to!string(decoded)); // prints: [77, 97, 114, 99, 111, 
110, 101] but I want to print: "Helo World!"
}