throwIfInstanceOf(throwable, IOException.class);
      throwIfUnchecked(throwable);
      throw new AssertionError(throwable); // not possible
    }
  }

  /** Suppression strategy interface. */
  @VisibleForTesting
  interface Suppressor {
    /**
     * Suppresses the given exception ({@code suppressed}) which was thrown when attempting to close

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

   * typically useful for {@code return} statements. That leaves the code with two options: Either
   * add the suppression to the whole method (which turns off checking for a large section of code),
   * or extract a variable, and put the suppression on that. However, a local variable typically
   * doesn't work: Because nullness analyses typically infer the nullness of local variables,

      suppressing.add(CollectionAddTester.getAddNullUnsupportedMethod());
      suppressing.add(CollectionAddAllTester.getAddAllNullUnsupportedMethod());
    }

    return newBuilderUsing(delegate, to, from)
        .named(parentBuilder.getName() + " subSet " + from + "-" + to)
        .withFeatures(features)
        .suppressing(suppressing)
        .withSetUp(parentBuilder.getSetUp())

      suppressing.add(CollectionAddTester.getAddNullUnsupportedMethod());
      suppressing.add(CollectionAddAllTester.getAddAllNullUnsupportedMethod());
    }

    return newBuilderUsing(delegate, to, from)
        .named(parentBuilder.getName() + " subSet " + from + "-" + to)
        .withFeatures(features)
        .suppressing(suppressing)
        .withSetUp(parentBuilder.getSetUp())

            .withFeatures(parentBuilder.getFeatures())
            .named(parentBuilder.getName() + " [Map]")
            .suppressing(parentBuilder.getSuppressedTests())
            .suppressing(SetCreationTester.class.getMethods())
            // BiMap.entrySet() duplicate-handling behavior is too confusing for SetCreationTester
            .withSetUp(parentBuilder.getSetUp())

            new MultimapGetGenerator<K, V>(parentBuilder.getSubjectGenerator()))
        .withFeatures(computeMultimapGetFeatures(parentBuilder.getFeatures()))
        .named(parentBuilder.getName() + ".get[key]")
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  @Override
  TestSuite computeMultimapAsMapGetTestSuite(
      FeatureSpecificTestSuiteBuilder<

   * {@link java.util.Collections#checkedCollection(java.util.Collection, Class)} can suppress it
   * with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug 6409434</a> is fixed.
   * It's unclear whether nulls were to be permitted or forbidden, but presumably the eventual fix

   * {@link java.util.Collections#checkedCollection(java.util.Collection, Class)} can suppress it
   * with {@code FeatureSpecificTestSuiteBuilder.suppressing()} until <a
   * href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6409434">Sun bug 6409434</a> is fixed.
   * It's unclear whether nulls were to be permitted or forbidden, but presumably the eventual fix