private String prettyPrintDefaultValue(Option o) {
		if (o.getDefaultValue() == null) {
			return "<none>";
		}
		return o.getDefaultValue()
				.replace("\n", "\\n")
				.replace("\t", "\\t")
				.replace("\f", "\\f");
	}
Escapes some special values so that they don't disturb console rendering and are easier to read.
spring-xd-shell/src/main/java/org/springframework/xd/shell/command/ModuleCommands.java