code: public void assertNotEmpty(Description description, Set<?> actual) {
      assertNotNull(description, actual);
      checkNotEmpty(description, actual);
    }
docs: Asserts that the given {@code Set} is not empty.
  
  @param description contains information about the assertion.
  @param actual the given {@code List}.
  @throws AssertionError if the given {@code Set} is {@code null}.
  @throws AssertionError if the given {@code Set} is not empty.