static <A, B, C> Map<B, C> lambdaMapLike safeMapToMap(IF1<A, Pair<B, C>> f, Iterable<A> l) {
  ret mapToMap(f, l);
}

static <A, B, C> Map<B, C> safeMapToMap(Iterable<A> l, IF1<A, Pair<B, C>> f) {
  ret mapToMap(f, l);
}

static <A, B, C, D> Map<C, D> safeMapToMap(IF2<A, B, Pair<C, D>> f, Map<A, B> m) {
  ret mapToMap(f, m);
}

Began life as a copy of #1024294