@Test
public void usageCommandDisplayedForUnknownCommand() throws CommandNotFoundException {
final String unknownCommand = "This is an Unknown Command";
ByteArrayOutputStream output = new ByteArrayOutputStream();
when(commandList.get(unknownCommand)).thenThrow(new CommandNotFoundException(unknownCommand));
System.setOut(new PrintStream(output, true));
assertUsageCommandRun(unknownCommand);
assertTrue("Unknown command should have displayed error Message", output.toString().contains("Unknown Command: " + unknownCommand));