private static boolean isImmutableMap(Map<?, ?> map) {
        return UNMODIFIABLE_MAP_CLASS.isInstance(map) || EMPTY_MAP_CLASS.isInstance(map);
    }
@return True if the provided map is an UnmodifiableMap or EmptyMap. Those classes are not
public hence we cannot use the `instanceof` operator.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/assignor/UniformHomogeneousAssignmentBuilder.java