@Override
	public String prompt(String prompt, String defaultValue, boolean echo) {
		InputStreamReader console = new InputStreamReader(System.in);
		System.out.format("%s: ", prompt);
		String answer = read(console, echo);
		return "".equals(answer) ? defaultValue : answer;
	}
Loops until one of the {@code options} is provided. Pressing return is equivalent to returning
{@code defaultValue}.
spring-xd-shell/src/main/java/org/springframework/xd/shell/command/ConsoleUserInput.java