### Question:
RealmUtils { public static String concatenateRealmPath(String parentRealm, String subrealm) { String realm; if (subrealm == null) { realm = parentRealm; } else { subrealm = cleanRealm(subrealm); if (parentRealm == null || parentRealm.equals("/")) { realm = subrealm; } else { realm = parentRealm + subrealm; } } return cleanRealm(realm); } private  RealmUtils(); static String getParentRealm(String path); static boolean isParentRealm(String parentPath, String path); static String getChildRealm(String path); static String cleanRealm(String realm); static String concatenateRealmPath(String parentRealm, String subrealm); @SuppressWarnings("unchecked") static Set<String> getRealmNames(SSOToken adminToken);  }### Answer:
@Test(dataProvider = "concatenateRealmPathData") public void shouldConcatenateRealmPath(String parentRealm, String subRealm, String expectedRealm) { assertThat(RealmUtils.concatenateRealmPath(parentRealm, subRealm)).isEqualTo(expectedRealm); }