### Question:
EmailBaseCommand implements ExecutableCommand { @Override public void executeCommand(CommandSender sender, List<String> arguments) { FoundCommandResult result = commandMapper.mapPartsToCommand(sender, Collections.singletonList("email")); helpProvider.outputHelp(sender, result, HelpProvider.SHOW_CHILDREN); }  @Override void executeCommand(CommandSender sender, List<String> arguments);  }### Answer:
@Test public void shouldDisplayHelp() { CommandSender sender = mock(CommandSender.class); FoundCommandResult result = mock(FoundCommandResult.class); given(commandMapper.mapPartsToCommand(eq(sender), anyList())).willReturn(result); command.executeCommand(sender, Collections.emptyList()); verify(commandMapper).mapPartsToCommand(sender, Collections.singletonList("email")); verify(helpProvider).outputHelp(sender, result, HelpProvider.SHOW_CHILDREN); }