private int crc3 = 0;

    @Override
    protected void process(ByteBuffer bb) {
      if (finished) {
        throw new IllegalStateException(
            "The behavior of calling any method after calling hash() is undefined.");
      }
      while (bb.remaining() >= 16) {
        crc0 = computeForWord(crc0);
        crc1 = computeForWord(crc1);
        crc2 = computeForWord(crc2);
        crc3 = computeForWord(crc3);

    return (existingCounter == null) ? 0 : existingCounter.get();
  }

  /**
   * {@inheritDoc}
   *
   * <p>If the data in the multiset is modified by any other threads during this method, it is
   * undefined which (if any) of these modifications will be reflected in the result.
   */
  @Override
  public int size() {
    long sum = 0L;
    for (AtomicInteger value : countMap.values()) {
      sum += value.get();

 * iterators</i>. This means that they are safe for concurrent use, but if other threads modify the
 * cache after the iterator is created, it is undefined which of these changes, if any, are
 * reflected in that iterator. These iterators never throw {@link ConcurrentModificationException}.
 *
 * <p><b>Note:</b> by default, the returned cache uses equality comparisons (the {@link

---

If you just don't know, use normal `def`.

---

**Note**: You can mix `def` and `async def` in your *path operation functions* as much as you need and define each one using the best option for you. FastAPI will do the right thing with them.

Anyway, in any of the cases above, FastAPI will still work asynchronously and be extremely fast.

//// tab | Python 3.8+

```Python hl_lines="31  37"
{!> ../../docs_src/response_model/tutorial006.py!}
```

////

## Recap

Use the *path operation decorator's* parameter `response_model` to define response models and especially to ensure private data is filtered out.

  if (op_reg_data->shape_inference_fn == nullptr) {
    status->status =
        InvalidArgument("No shape inference function exists for op '",
                        node_def.op(), "', did you forget to define it?");
    return;
  }

  status->status = c.Run(op_reg_data->shape_inference_fn);
  if (!status->status.ok()) return;

  // Set output_shapes.
  TF_ShapeAndTypeList* output_shapes_result =

    val receiveBuffer = Buffer()

    /** Buffer with readable data. Guarded by Http2Stream.this. */
    val readBuffer = Buffer()

    /**
     * Received trailers. Null unless the server has provided trailers. Undefined until the stream
     * is exhausted. Guarded by Http2Stream.this.
     */
    var trailers: Headers? = null

    /** True if the caller has closed this stream. */
    internal var closed: Boolean = false

  // and identical values are considered to be in the same topology.
  // We consider each <key, value> as a "bucket", and try to put balanced number
  // of pods into each bucket.
  // We define a domain as a particular instance of a topology.
  // Also, we define an eligible domain as a domain whose nodes meet the requirements of
  // nodeAffinityPolicy and nodeTaintsPolicy.

                .build());
        options.addOption(Option.builder(Character.toString(SET_USER_PROPERTY))
                .numberOfArgs(2)
                .valueSeparator('=')
                .desc("Define a user property")
                .build());
        options.addOption(Option.builder(Character.toString(OFFLINE))
                .longOpt("offline")
                .desc("Work offline")
                .build());

     *
     * That combination upsets NullPointerTester, which wants any call that passes null for a
     * non-@Nullable parameter to trigger a NullPointerException.
     *
     * (We still define this empty method to keep PackageSanityTests from generating its own
     * automated nullness tests, which would fail.)
     */
  }

  private static final Object IGNORE_ME =
      new Object() {