}

  /**
   * Returns a resolver that resolves types "covariantly".
   *
   * <p>For example, when resolving {@code List<T>} in the context of {@code ArrayList<?>}, {@code
   * <T>} is covariantly resolved to {@code <?>} such that return type of {@code List::get} is
   * {@code <?>}.
   */
  static TypeResolver covariantly(Type contextType) {

  }

  /**
   * Returns a resolver that resolves types "covariantly".
   *
   * <p>For example, when resolving {@code List<T>} in the context of {@code ArrayList<?>}, {@code
   * <T>} is covariantly resolved to {@code <?>} such that return type of {@code List::get} is
   * {@code <?>}.
   */
  static TypeResolver covariantly(Type contextType) {

      FeatureSpecificTestSuiteBuilder<
              ?, ? extends OneSizeTestContainerGenerator<Map<K, V>, Entry<K, V>>>
          parentBuilder) {
    // TODO: Once invariant support is added, supply invariants to each of the
    // derived suites, to check that mutations to the derived collections are
    // reflected in the underlying map.

  @Override
  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<M, Entry<K, V>>>
          parentBuilder) {
    // TODO: Once invariant support is added, supply invariants to each of the
    // derived suites, to check that mutations to the derived collections are
    // reflected in the underlying map.

    when {
      value != null -> LinkedTags(key, value, this)
      else -> this
    }

  override fun <T : Any> get(key: KClass<T>): T? = null

  override fun toString() = "{}"
}

/**
 * An invariant of this implementation is that [next] must not contain a mapping for [key].
 * Otherwise, we would have two values for the same key.
 */
private class LinkedTags<K : Any>(
  private val key: KClass<K>,

   *
   * <p>Normally this method leaves the elements at up to {@code index - 1}, inclusive, untouched.
   * Under these circumstances, it returns {@code null}.
   *
   * <p>Occasionally, in order to maintain the heap invariant, it must swap a later element of the
   * list with one before {@code index}. Under these circumstances it returns a pair of elements as

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;
        return;

    assertThat(cache.size()).isEqualTo(1);
    assertThat(cache.getUnchecked("b")).isEqualTo("b");
  }

  // "Basher tests", where we throw a bunch of stuff at a LoadingCache and check basic invariants.

  /**
   * This is a less carefully-controlled version of {@link #testRemovalNotification_clear} - this is
   * a black-box test that tries to create lots of different thread-interleavings, and asserts that

      // before the cancelled future completes, it will synchronously complete both the newFuture
      // from the cancelled operation and its own. This can cause one runnable to queue two tasks,
      // breaking the invariant this method relies on to iteratively run the next task after the
      // previous one completes.
      if (get() == RunningState.CANCELLED) {
        delegate = null;
        sequencer = null;
        return;

	return append(dst, pre)
}

// fileState tracks the number of logical (includes sparse holes) and physical
// (actual in tar archive) bytes remaining for the current file.
//
// Invariant: logicalRemaining >= physicalRemaining
type fileState interface {
	logicalRemaining() int64
	physicalRemaining() int64
}

// allowedFormats determines which formats can be used.