} catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testEntrySetRetainAllNullFromEmpty() {
    try {
      super.testEntrySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().retainAll(null) doesn't throws NPE.
    }
  }

  @Override

        int len = this.length;

        if ( this.next != null ) {
            int nextStart = dstIndex;
            dstIndex += this.next.encode(dst, dstIndex);
            int off = nextStart - start;
            SMBUtil.writeInt4(off, dst, start + 20);
            len += dstIndex - nextStart;
        }

        if ( this.digest != null ) {

   * {@link Equivalence#equivalent} returns {@code true} if both values are null, or if neither
   * value is null and {@link Object#equals} returns {@code true}. {@link Equivalence#hash} returns
   * {@code 0} if passed a null value.
   *
   * @since 13.0
   * @since 8.0 (in Equivalences with null-friendly behavior)
   * @since 4.0 (in Equivalences)
   */
  public static Equivalence<Object> equals() {

    }
    if (keyStrength != null) {
      s.add("keyStrength", Ascii.toLowerCase(keyStrength.toString()));
    }
    if (valueStrength != null) {
      s.add("valueStrength", Ascii.toLowerCase(valueStrength.toString()));
    }
    if (keyEquivalence != null) {
      s.addValue("keyEquivalence");
    }
    if (valueEquivalence != null) {
      s.addValue("valueEquivalence");
    }

    val mainMethod =
      Class.forName(className)
        .methods.find { it.name == "main" }
    try {
      if (mainMethod != null) {
        if (mainMethod.parameters.isEmpty()) {
          mainMethod.invoke(null)
        } else {
          mainMethod.invoke(null, arrayOf<String>())
        }
      } else {
        System.err.println("No main for $className")
      }

      assertThrows(NullPointerException.class, () -> entry.setValue(null));
      expectUnchanged();
    }
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testSetValueNullSupported() {
    for (Entry<K, V> entry : getMap().entrySet()) {
      if (entry.getKey().equals(k0())) {
        entry.setValue(null);
      }
    }
    expectReplacement(entry(k0(), (V) null));

  }

  public void testToOptionalSingleton() {
    assertThat(Stream.of(1).collect(toOptional())).hasValue(1);
  }

  public void testToOptionalNull() {
    Stream<@Nullable Object> stream = Stream.of((Object) null);
    assertThrows(NullPointerException.class, () -> stream.collect(toOptional()));
  }

  public void testToOptionalMultiple() {
    IllegalArgumentException expected =

     */
    @Override
    public int encode ( byte[] dst, int dstIndex ) {
        int start = dstIndex;
        SMBUtil.writeInt2(this.ciphers != null ? this.ciphers.length : 0, dst, dstIndex);
        dstIndex += 2;

        if ( this.ciphers != null ) {
            for ( int cipher : this.ciphers ) {
                SMBUtil.writeInt2(cipher, dst, dstIndex);
                dstIndex += 2;
            }
        }

    /**
     * Gets the policy that applies to this metadata regarding the specified repository.
     *
     * @param repository The repository for which to determine the policy, must not be {@code null}.
     * @return The policy, never {@code null}.
     */
    ArtifactRepositoryPolicy getPolicy(ArtifactRepository repository);

    }

    @Test
    void testOneProblem() {
        ProblemCollector problemCollector = ProblemCollectorFactory.newInstance(null);
        problemCollector.add(Problem.Severity.ERROR, "MESSAGE", 3, 5, new Exception());
        ToolchainsBuildingException e = new ToolchainsBuildingException(problemCollector.getProblems());
        assertEquals(