code: public Map<String, Object> getMixins() {
          Map<String, CommandSpec> mixins = getCommandSpec().mixins();
          Map<String, Object> result = new LinkedHashMap<String, Object>();
          for (String name : mixins.keySet()) { result.put(name, mixins.get(name).userObject); }
          return result;
      }
docs: Returns a map of user objects whose options and positional parameters were added to ("mixed in" with) this command.
  @return a new Map containing the user objects mixed in with this command. If {@code CommandSpec} objects without
  user objects were programmatically added, use the {@link CommandSpec#mixins() underlying model} directly.
  @since 3.0