@GwtCompatible
@ElementTypesAreNonnullByDefault
final class RelationshipTester<T> {

  static class ItemReporter {
    String reportItem(Item<?> item) {
      return item.toString();
    }
  }

  /**
   * A word about using {@link Equivalence}, which automatically checks for {@code null} and
   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class

@GwtCompatible
@ElementTypesAreNonnullByDefault
final class RelationshipTester<T> {

  static class ItemReporter {
    String reportItem(Item<?> item) {
      return item.toString();
    }
  }

  /**
   * A word about using {@link Equivalence}, which automatically checks for {@code null} and
   * identical inputs: This sounds like it ought to be a problem here, since the goals of this class