### Question:
RequiredValueValidator implements ServiceAttributeValidator { public boolean validate(Set<String> values) { if (values.size() > 0) { for (String value : values) { if (!StringUtils.isNotEmpty(value)) { return false; } } return true; } return false; }  boolean validate(Set<String> values);  }### Answer:
@Test public void checkReturnFalseIfEmptySet() { boolean result = validator.validate(Collections.<String>emptySet()); assertThat(result).isEqualTo(false); }
@Test public void checkReturnFalseIfEmptyStringInSet() { boolean result = validator.validate(Collections.singleton("")); assertThat(result).isEqualTo(false); }
@Test public void checkReturnTrueIfBlankStringInSet() { boolean result = validator.validate(Collections.singleton(" ")); assertThat(result).isEqualTo(true); }
@Test public void checkReturnTrueIfSetValid() { HashSet<String> set = new HashSet<>(); set.add("one"); set.add("two"); set.add("three"); set.add("four"); boolean result = validator.validate(set); assertThat(result).isEqualTo(true); }
@Test public void checkReturnFalseIfSetInvalid() { HashSet<String> set = new HashSet<>(); set.add("one"); set.add("two"); set.add("three"); set.add(""); boolean result = validator.validate(set); assertThat(result).isEqualTo(false); }