public static <I extends Iterable<E>, E> IterableChecker<I, E> check(@Nullable I actualValue) {
    return new IterableChecker<>(actualValue, false);
  }
Convenient wrappers for matcher checking, designed for better code assist(completion) and
discoverability for most commonly used matchers.
testing/src/org/immutables/check/Checkers.java