// module ID => sticky library IDs
static MultiMap<S> dm_stickyLibsByModule() {
  new MultiMap<S> mm;
  for (S mod : dm_listModuleIDs()) {
    O main = dm_modMainClass(mod);
    for (S field : fieldNames(main))
      if (eq(field, '_stickyLibs) || startsWith(field, "_stickyLibs_")) pcall {
        mm.putAll(mod, (Collection<S>) get(main, field));
      }
  }
  ret uniquifyMultiMapValues(mm);
}