你可以设置*路径操作装饰器*的 `response_model_exclude_unset=True` 参数：

{* ../../docs_src/response_model/tutorial004.py hl[24] *}

然后响应中将不会包含那些默认值，而是仅有实际设置的值。

因此，如果你向*路径操作*发送 ID 为 `foo` 的商品的请求，则响应（不包括默认值）将为：

```JSON
{
    "name": "Foo",
    "price": 50.2
}
```

/// info

                try {
                  barrier.await();
                } catch (Exception e) {
                  throw new AssertionError(e);
                }

                dispatcher.dispatch("foo", stringSubscribers.iterator());
                latch.countDown();
              }
            })
        .start();

    Uninterruptibles.awaitUninterruptibly(latch);

                </div>
            </div>
        </section>
    </main>
    <jsp:include page="/WEB-INF/view/common/admin/footer.jsp"></jsp:include>
</div>
<jsp:include page="/WEB-INF/view/common/admin/foot.jsp"></jsp:include>
</body>

  private void weaklyReferenceQueue() {
    frq = new FinalizableReferenceQueue();
    queueReference = new WeakReference<>(frq.queue);

    /*
     * Queue and clear a reference for good measure. We test later on that
     * the finalizer thread stopped, but we should test that it actually
     * started first.
     */
    reference =
        new FinalizableWeakReference<Object>(new Object(), frq) {

 * values without specific replacements are to be considered safe and left unescaped or should be
 * escaped in a general way.
 *
 * <p>A good example of usage of this class is for Java source code escaping where the replacement
 * array contains information about special ASCII characters such as {@code \\t} and {@code \\n}

func (c Context) MarshalText() ([]byte, error) {
	if len(c) == 0 {
		return []byte{'{', '}'}, nil
	}

	// Pre-allocate a buffer - 128 bytes is an arbitrary
	// heuristic value that seems like a good starting size.
	b := bytes.NewBuffer(make([]byte, 0, 128))
	if len(c) == 1 {
		for k, v := range c {
			b.WriteString(`{"`)
			escapeStringJSON(b, k)
			b.WriteString(`":"`)
			escapeStringJSON(b, v)

   * and will be really slow if we regress the fix for that.
   */
  @Test
  fun `reading a large part with small byteCount`() {
    val multipartBody =
      MultipartBody
        .Builder("foo")
        .addPart(
          headersOf("header-name", "header-value"),
          object : RequestBody() {
            override fun contentType() = "application/octet-stream".toMediaTypeOrNull()

#### Шлях (path)

"Шлях" це частина URL, яка йде одразу після символу `/`.

Отже, у такому URL, як:

```
https://example.com/items/foo
```

...шлях буде:

```
/items/foo
```

/// info | Додаткова інформація

"Шлях" (path) також зазвичай називають "ендпоінтом" (endpoint) або "маршрутом" (route).

///

    public void testValueExtractorWithAInvalidExpression() throws Exception {
        assertNull(ReflectionValueExtractor.evaluate("project.foo", project));
        assertNull(ReflectionValueExtractor.evaluate("project.dependencies[10]", project));
        assertNull(ReflectionValueExtractor.evaluate("project.dependencies[0].foo", project));
    }

    /**
     * <p>testMappedDottedKey.</p>
     *
     * @throws Exception if any.
     */

              <!-- TODO(cpovirk): Enable NullArgumentForNonNullParameter for
                   prod code. It's disabled automatically for "test code"
                   (which is good: our tests have intentional violations), but
                   Error Prone doesn't know it's building test code unless we
                   pass -XepCompilingTestOnlyCode, and that argument needs to