@Override
      public Attribute isNot(Object value) throws IOException {
        Object actualValue = Files.getAttribute(actual, attribute, linkOptions);
        check("attribute(%s)", attribute).that(actualValue).isNotEqualTo(value);
        return this;
      }
Returns an object for making assertions about the given attribute.
jimfs/src/test/java/com/google/common/jimfs/PathSubject.java