### Question:
DefaultCommandManager implements CommandManager { @NotNull @Override public List<String> suggest(@NotNull String commandLine, @NotNull CommandSender commandSender) { String[] split = commandLine.split(" "); CommandContainer command = this.getCommand(commandSender, split); if (command == null) { return new ArrayList<>(); } int argumentIndex = (commandLine.length() - commandLine.replace(" ", "").length()) - 1; String[] args = split.length > 1 ? Arrays.copyOfRange(split, 1, split.length) : new String[0]; try { return command.getCommand().suggest(commandSender, args, argumentIndex, commandLine); } catch (Throwable throwable) { System.err.println("Exception tab completing command \"" + split[0] + "\" with arguments " + String.join(", ", args)); throwable.printStackTrace(); } return new ArrayList<>(); }  @Override @NotNull CommandManager registerCommand(@NotNull Command command, @NotNull String description, @NotNull List<String> aliases); @Override void unregisterCommand(@NotNull CommandContainer command); @Override void unregisterCommand(@NotNull String... aliases); @NotNull @Override Optional<CommandContainer> getCommand(@NotNull String anyAlias); @NotNull @Override @UnmodifiableView Collection<CommandContainer> getCommands(); @Override boolean process(@NotNull String commandLine, @NotNull CommandSender commandSender); @NotNull @Override List<String> suggest(@NotNull String commandLine, @NotNull CommandSender commandSender);  }### Answer:
@Test @Order(5) void testCommandSuggest() { List<String> suggest = this.commandManager.suggest("test 45 343 432", ConsoleCommandSender.INSTANCE); Assertions.assertEquals(1, suggest.size()); Assertions.assertEquals("test", suggest.get(0)); }