public boolean unregister(String name) {
        AnnotationType oldType = nameMap.remove(name);
        if (oldType != null) {
            idMap.remove(oldType.getId());
            return true;
        }
        return false;
    }
Unregisters the type given by the argument.
WARNING! Only to be used by the configuration system and in unit tests. Not to be used in production code.

@param name the name of the type to unregister
@return true if the type was successfully unregistered, false otherwise (it was not present)
document/src/main/java/com/yahoo/document/annotation/AnnotationTypeRegistry.java