static <A, B> Map<A, B> combinedMap(Map<A, B>... maps) {
  ret CombinedMap(wrapAsList(maps));
}

static <A, B, C extends Map<A, B>> Map<A, B> combinedMap(Collection<C> maps) {
  ret l(maps) == 1 ? first(maps) : CombinedMap(maps);
}