private String provided(String annotationType) {
        if (provided==null) return null;
        for (Annotation a : provided) {
            if (a.type.equals(annotationType)) return a.clazz;
        }
        return null;
    }
The class for this type if provided, otherwise null
vespa-documentgen-plugin/src/main/java/com/yahoo/vespa/DocumentGenMojo.java