Sample JUnit

gistfile1.java

    public String railways(String name, Void _ignoreError) {
        return "SUCCESS";
    }

    public String railways(Void _ignoreName, String error) {
        return "FAILURE";
    }

    @Test
    public void workingWithEither() {
        assertThat(railways("Any Name", null), is(equalTo("SUCCESS")));
        assertThat(railways(null, "Any Error"), is(equalTo("FAILURE")));
    }