@SuppressWarnings("OptionalUsedAsFieldOrParameterType")
  default R is(OptionalInt optional) {
    Objects.requireNonNull(optional, "optional");
    return optional.isPresent() ? is(optional.getAsInt()) : isAbsent();
  }
Intersection type between {@link OptionalObjectMatcher} and {@link NumberMatcher}.

<p>Syntax sugar to avoid chaining {@code value()} method from {@link OptionalObjectMatcher}
on long expressions with many optional elements.

@param <R> root criteria type
criteria/common/src/org/immutables/criteria/matcher/OptionalIntegerMatcher.java