@GwtIncompatible
  @Deprecated
  public static RuntimeException propagate(Throwable throwable) {
    throwIfUnchecked(throwable);
    throw new RuntimeException(throwable);
  }

  /**
   * Returns the innermost cause of {@code throwable}. The first throwable in a chain provides
   * context from when the error or exception was initially detected. Example usage:
   *
   * <pre>

            new TestStringListGenerator() {
              @Override
              public List<String> create(String[] elements) {
                List<String> innerList = new ArrayList<>();
                Collections.addAll(innerList, elements);
                return unmodifiableList(innerList);
              }
            })
        .named("unmodifiableList/ArrayList")
        .withFeatures(
            CollectionFeature.SERIALIZABLE,