* "plain {@code T}." This API provides that.
   */
  @SuppressWarnings({"nullness", "TypeParameterUnusedInFormals", "ReturnMissingNullable"})
  // The warnings are legitimate. Each time we use this method, we document why.
  @ParametricNullness
  static <T extends @Nullable Object> T uncheckedNull() {
    return null;
  }

  private NullnessCasts() {}

     * <p>
     * Initializes the ThreadLocal Kryo instances with appropriate configuration.
     * The Kryo instances are configured to not require class registration for
     * flexibility, and debug mode warnings are enabled when debug logging is active.
     * </p>
     */
    public DataSerializer() {
        kryoThreadLocal = ThreadLocal.withInitial(() -> {
            final Kryo kryo = new Kryo();

   * more futures or adding more {@code directExecutor()} listeners inline -- consider {@link
   * MoreExecutors#directExecutor}. Otherwise, avoid it: See the warnings on the docs for {@code
   * directExecutor}.
   *
   * <p>This is the most general listener interface. For common operations performed using

   * more futures or adding more {@code directExecutor()} listeners inline -- consider {@link
   * MoreExecutors#directExecutor}. Otherwise, avoid it: See the warnings on the docs for {@code
   * directExecutor}.
   *
   * <p>This is the most general listener interface. For common operations performed using

              restoreInterruptIfIsInterruptedException(e);
              logger.get().log(WARNING, "thrown by close()", e);
            }
          });
    } catch (RejectedExecutionException e) {
      if (logger.get().isLoggable(WARNING)) {
        logger
            .get()
            .log(
                WARNING,
                String.format("while submitting close to %s; will close inline", executor),

        writeTestFile("invalid => "); // Invalid format

        try {
            charMappingFile.reload(null);
            // If no exception, the file might have been parsed with warnings
            assertTrue(true);
        } catch (Exception e) {
            // Expected for invalid format
            assertTrue(true);
        }
    }

      for (index in 0 until cachedHeaders.size) {
        val fieldName = cachedHeaders.name(index)
        val value = cachedHeaders.value(index)
        if ("Warning".equals(fieldName, ignoreCase = true) && value.startsWith("1")) {
          // Drop 100-level freshness warnings.
          continue
        }
        if (isContentSpecificHeader(fieldName) ||
          !isEndToEnd(fieldName) ||
          networkHeaders[fieldName] == null

      }
    }

    /*
     * TODO(cpovirk): `return (V) removedValue` once our checker permits that.
     *
     * (We promoted a class of warnings into errors because sometimes they indicate real problems.
     * But now we need to "undo" some instance of spurious errors, as discussed in
     * https://github.com/jspecify/checker-framework/issues/8.)
     */

    @Test
    void testUnwrap_typeSafety() {
        CustomSmbTree customTree = mock(CustomSmbTree.class);
        when(smbTree.unwrap(CustomSmbTree.class)).thenReturn(customTree);

        // This should compile without warnings
        CustomSmbTree typedResult = smbTree.unwrap(CustomSmbTree.class);

        assertNotNull(typedResult, "Typed result should not be null");
        assertEquals(customTree, typedResult, "Should maintain type safety");

 *       collection whose contents should be copied.
 *   <li>A static nested {@code Builder} class which can be used to populate a new immutable
 *       instance.
 * </ul>
 *
 * <h4>Warnings</h4>
 *
 * <ul>
 *   <li><b>Warning:</b> as with any collection, it is almost always a bad idea to modify an element
 *       (in a way that affects its {@link Object#equals} behavior) while it is contained in a