public class Runner {

    interface Lambda {
        String doSomething(String parameter);
    }

    public static void main(String[] args) {

        Lambda lambda1 = parameter1 -> "any";
        Lambda lambda2 = parameter2 -> "any";
        Lambda lambda3 = parameter3 -> "any";

        check("parameter1", getNameArgument(lambda1));
        check("parameter2", getNameArgument(lambda2));
        check("parameter3", getNameArgument(lambda3));

    }

    private static void check(String expected, String actual){
        if (!expected.equals(actual)) {
            throw new RuntimeException("you've written bad method");
        }
    }

    public static String getNameArgument(Ihar ihar) {
        // need to write method, that returns lambda's name argument
        return null;
    }
}