constituent.getType(),
                constituent.getClassifier(),
                constituent.getVersion());
    }

    private static String getId(String gid, String aid, String type, String cls, String ver) {
        return gid + ':' + aid + ':' + type + ((cls != null && !cls.isEmpty()) ? ':' + cls : "") + ':' + ver;
    }

    private void callDelegates(
            ClassRealm classRealm,
            RealmType type,

 * reference. It allows you to represent "a {@code T} that must be present" and a "a {@code T} that
 * might be absent" as two distinct types in your program, which can aid clarity.
 *
 * <p>Some uses of this class include
 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available

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