code: public CommandLine setResourceBundle(ResourceBundle bundle) {
          getCommandSpec().resourceBundle(bundle);
          for (CommandLine command : getCommandSpec().subcommands().values()) {
              command.getCommandSpec().resourceBundle(bundle);
          }
          return this;
      }
docs: Sets the ResourceBundle containing usage help message strings.
  <p>The specified bundle will be registered with this {@code CommandLine} and the full hierarchy of its
  subcommands and nested sub-subcommands <em>at the moment this method is called</em>. Subcommands added
  later will not be impacted. To ensure a setting is applied to all
  subcommands, call the setter last, after adding subcommands.</p>
  @param bundle the ResourceBundle containing usage help message strings
  @return this {@code CommandLine} object, to allow method chaining
  @see Command#resourceBundle()
  @see CommandSpec#resourceBundle(ResourceBundle)
  @since 3.6