private DefaultToolchainsReader reader = new DefaultToolchainsReader();

    @Test
    void testMergeNulls() {
        merger.merge(null, null, null);

        PersistedToolchains pt = new PersistedToolchains();
        merger.merge(pt, null, null);
        merger.merge(null, pt, null);
    }

    @Test
    void testMergeJdk() throws Exception {

        public String getUNCPath() {
            return null;
        }

        @Override
        public String getURLPath() {
            return null;
        }

        @Override
        public String getShare() {
            return null;
        }

        @Override
        public String getServerWithDfs() {
            return null;
        }

        @Override

    /**
     * Returns {@link Artifact} instance where to relocate to, or {@code null}.
     *
     * @param session The session, never {@code null}.
     * @param result The artifact descriptor result, never {@code null}.
     * @param model The artifact model, never {@code null}.
     * @return The {@link Artifact} to relocate to, or {@code null} if no relocation wanted.
     */

    this.singleValue = singleValue;
    this.inverse = null;
  }

  private SingletonImmutableBiMap(K singleKey, V singleValue, ImmutableBiMap<V, K> inverse) {
    this.singleKey = singleKey;
    this.singleValue = singleValue;
    this.inverse = inverse;
  }

  @Override
  public @Nullable V get(@Nullable Object key) {
    return singleKey.equals(key) ? singleValue : null;
  }

  @Override
  public int size() {

        // The server name is stored in a protected field without a public getter, so we cannot directly test it.
        // We can test the public fields that are set.
        assertEquals(200, dfsRootEnum.level, "The level should be initialized to 200.");
        assertNotNull(dfsRootEnum.info, "The info struct should not be null.");

        when(mockConfig.isDfsDisabled()).thenReturn(false);
        when(mockContext.getCredentials()).thenReturn(mockCredentials);
        when(mockCredentials.getUserDomain()).thenReturn(null);
        assertFalse(dfsResolver.isTrustedDomain(mockContext, "anyDomain"));
    }

    @Test
    void testIsTrustedDomain_EmptyUserDomain() throws CIFSException {

    @Test
    public void test_getTook() throws Exception {
        SuggestDeleteResponse response = new SuggestDeleteResponse(null, 250);

        assertEquals(250, response.getTook());
    }

    @Test
    public void test_hasError() throws Exception {
        SuggestDeleteResponse response1 = new SuggestDeleteResponse(null, 100);
        assertFalse(response1.hasError());

        List<Throwable> errors = new ArrayList<>();

      queue[size] = null;
      return null;
    }
    E toTrickle = elementData(size);
    queue[size] = null;
    MoveDesc<E> changes = fillHole(index, toTrickle);
    if (lastElementAt < index) {
      // Last element is moved to before index, swapped with trickled element.
      if (changes == null) {
        // The trickled element is still after index.

    }
  }

  /*
   * Preconditions.checkNotNull is *intended* for performing eager null checks on parameters that a
   * nullness checker can already "prove" are non-null. That means that the first parameter to
   * checkNotNull *should* be annotated to require it to be non-null.
   *
   * However, for a variety of reasons, Google developers have written a ton of code over the past

    public byte[] getContextHandle() {
        return contextHandle != null ? contextHandle.clone() : null;
    }

    /**
     * Sets the context handle.
     *
     * @param contextHandle the context handle
     */
    public void setContextHandle(byte[] contextHandle) {
        this.contextHandle = contextHandle != null ? contextHandle.clone() : null;
    }

    @Override