@Test
    void testPlural_1() {
        assertThat(plural("has", "have", 1))
                .isEqualTo("has");
        assertThat(plural("has", "have", 2))
                .isEqualTo("have");
    }
Make sure the two functions are reversible
stroom-util-shared/src/test/java/stroom/util/shared/TestStringUtil.java