I can't figure out how to test this. Tell me please good literature or vebinar on this topic
public InputMessenger getInputForMessengerFromConsole() {
String templateValue;
Map<String, String> valuesForTemplate = new HashMap<>();
try (Scanner scanner = new Scanner(System.in, Constant.CHARSET_NAME_UTF_8)) {
System.out.println(Constant.MESSAGE_INPUT_TEMPLATE);
templateValue = scanner.nextLine();
System.out.println(Constant.MESSAGE_NUMBER_OF_VALUES);
int numberOfValues = scanner.nextInt();
scanner.nextLine();
IntStream.range(0, numberOfValues).forEach(index -> {
System.out.println(Constant.MESSAGE_KEY + (index + Constant.INT_ONE) + Constant.COLON);
String key = scanner.nextLine();
System.out.println(Constant.MESSAGE_VALUE + (index + Constant.INT_ONE) + Constant.COLON);
String value = scanner.nextLine();
valuesForTemplate.put(key, value);
});
}
return new InputMessenger(templateValue, valuesForTemplate);
}