} catch (NoSuchAlgorithmException e) {
      throw new AssertionError(e);
    }
  }

  @Override
  public Hasher newHasher() {
    if (supportsClone) {
      try {
        return new MessageDigestHasher((MessageDigest) prototype.clone(), bytes);
      } catch (CloneNotSupportedException e) {
        // falls through
      }
    }
    return new MessageDigestHasher(getMessageDigest(prototype.getAlgorithm()), bytes);

    }

    /**
     * Constructs a new CrawlerSystemException with the specified detail message.
     *
     * @param message the detail message. The detail message is saved for later retrieval by the {@link #getMessage()} method.
     */
    public CrawlerSystemException(final String message) {
        super(message);
    }

    /**
     * Constructs a new CrawlerSystemException with the specified cause.
     *

    return new CollectionTestSuiteBuilder<E>().usingGenerator(generator);
  }

  @Override
  protected List<TestSuite> createDerivedSuites(
      FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<E>, E>>
          parentBuilder) {
    List<TestSuite> derivedSuites = new ArrayList<>(super.createDerivedSuites(parentBuilder));

    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

            // last resort; as ideally we should get ExitException only
            new SystemLogger(stdErr).error(e.getMessage(), e);
            return 1;
        } finally {
            if (classWorldManaged) {
                classWorld.close();
            }
        }
    }

    protected MessageBuilderFactory createMessageBuilderFactory() {
        return new JLineMessageBuilderFactory();
    }

    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));
  }

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> from(Collection<? extends E> contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], contents);
  }

  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTestSuite(ForwardingSortedSetTest.class);
    suite.addTest(
        SortedSetTestSuiteBuilder.using(
                new TestStringSortedSetGenerator() {
                  @Override
                  protected SortedSet<String> create(String[] elements) {
                    return new StandardImplForwardingSortedSet<>(

        URL docResource;
        try {
            docResource = new File(myClasspathEntry).toURL();
        } catch (MalformedURLException e) {
            throw new ExpressionDocumentationException(
                    "Cannot construct expression documentation classpath" + " resource base.", e);
        }

        return new URLClassLoader(new URL[] {docResource});
    }

  }

  public SafeTreeMap(Map<? extends K, ? extends V> map) {
    this(new TreeMap<K, V>(map));
  }

  public SafeTreeMap(SortedMap<K, ? extends V> map) {
    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = delegate;
    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {

    @Override
    public Map<String, String> getUserProperties() {
        return Collections.unmodifiableMap(new PropertiesAsMap(getMavenSession().getUserProperties()));
    }

    @Nonnull
    @Override
    public Map<String, String> getSystemProperties() {
        return Collections.unmodifiableMap(new PropertiesAsMap(getMavenSession().getSystemProperties()));
    }

    @Nonnull
    @Override