public static String getPrefixedNameFor(String accountName, String issuer) {
    return new AccountIndex(accountName, issuer).toString();
  }
If the {@code issuer} is set, returns a fully qualified string of the form {@code
"issuer:name"}, e.g., {@code "Google:bob@example.com"}. If no {@code issuer} is set, returns
just the account name.
java/com/google/android/apps/authenticator/otp/AccountDb.java