java 8 remove duplicate object in List

자바 8으로 객체 리스트의 중복 데이터 제거하기

@Test
public void testaa() {
    List<test> list = Arrays.asList(
            new test("test1","email1","option1"),
            new test("test1","email1","option2"),
            new test("test1","email1","option3"),
            new test("test1","email1","option3")
    );

    System.out.println(list.size());

    List<test> list2 = new ArrayList<>();
    //note: getOption 으로 비교
    list2.addAll(list.stream().collect(Collectors.toConcurrentMap(test::getOption, Function.identity(), (p, q) -> p)).values());
    for (test t:list2) {
        System.out.println(t.option);
    }
}
class test{
    private String name;
    private String email;
    private String option;

    public test(String name, String email, String option) {
        this.name = name;
        this.email = email;
        this.option = option;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getOption() {
        return option;
    }

    public void setOption(String option) {
        this.option = option;
    }
}