if (classpath == null || classpath.isEmpty()) {
            return null;
        }

        MetadataTreeNode tree = null;
        MetadataTreeNode parent = null;

        for (ArtifactMetadata md : classpath) {
            MetadataTreeNode node = new MetadataTreeNode(md, parent, md.isResolved(), md.getArtifactScope());
            if (tree == null) {
                tree = node;
            }

        if (project.getDependencyArtifacts() == null) {
            for (Dependency dependency : project.getDependencies()) {
                if (dependency.getGroupId() == null
                        || dependency.getGroupId().isEmpty()
                        || dependency.getArtifactId() == null
                        || dependency.getArtifactId().isEmpty()

    assertEquals("correct", f.apply(new Object()));
    assertEquals("correct", f.apply(null));

    Function<@Nullable Object, @Nullable String> g = Functions.constant(null);
    assertEquals(null, g.apply(2));
    assertEquals(null, g.apply(null));

    new EqualsTester()
        .addEqualityGroup(f, Functions.constant("correct"))

        synchronized (Deferred.this) {
            if (response != null || error != null) {
                return;
            }
            response = r;

            executeCallbacks = new ArrayList<>(doneCallbacks.size());
            Consumer<RESPONSE> callback;
            while ((callback = doneCallbacks.poll()) != null) {
                executeCallbacks.add(callback);
            }
        }

   *     for the keys
   */
  @CanIgnoreReturnValue
  public @Nullable V erase(@Nullable Object rowKey, @Nullable Object columnKey) {
    Integer rowIndex = rowKeyToIndex.get(rowKey);
    Integer columnIndex = columnKeyToIndex.get(columnKey);
    if (rowIndex == null || columnIndex == null) {
      return null;
    }

        @Test
        @DisplayName("getBytes should handle null string")
        void testGetBytesWithNull() {
            // When
            byte[] result = Strings.getBytes(null, StandardCharsets.UTF_8);

            // Then
            assertNotNull(result, "Should return non-null array");
            assertEquals(0, result.length, "Should return empty array for null string");
        }

        @Test

   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);

interface ModelCacheTag<T> {

    /**
     * Gets the name of the tag.
     *
     * @return The name of the tag, must not be {@code null}.
     */
    String getName();

    /**
     * Gets the type of data associated with this tag.
     *
     * @return The type of data, must not be {@code null}.
     */
    Class<T> getType();

    /**

   *
   * @param escaper the non-null escaper to test
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);

  public void testPutIfAbsent_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)