위 예에서 `skip=0`과 `limit=10`은 기본값을 갖고 있습니다.

그러므로 URL로 이동하는 것은:

```
http://127.0.0.1:8000/items/
```

아래로 이동하는 것과 같습니다:

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

하지만 가령 아래로 이동한 경우:

```
http://127.0.0.1:8000/items/?skip=20
```

함수의 매개변수 값은 아래가 됩니다:

* `skip=20`: URL에서 지정했기 때문입니다
* `limit=10`: 기본값이기 때문입니다

## 선택적 매개변수

## 默认值

查询参数不是路径的固定内容，它是可选的，还支持默认值。

上例用 `skip=0` 和 `limit=10` 设定默认值。

访问 URL：

```
http://127.0.0.1:8000/items/
```

与访问以下地址相同：

```
http://127.0.0.1:8000/items/?skip=0&limit=10
```

但如果访问：

```
http://127.0.0.1:8000/items/?skip=20
```

查询参数的值就是：

* `skip=20`：在 URL 中设定的值
* `limit=10`：使用默认值

## 可选参数

同理，把默认值设为 `None` 即可声明**可选的**查询参数：

      - apiGroups:
          - ""
        apiVersions:
          - v1
        operations:
          - CREATE
        resources:
          - pods
        scope: '*'
    sideEffects: None
    timeoutSeconds: 10
  - admissionReviewVersions:
      - v1beta1
      - v1
    clientConfig:
      service:
        name: istiod
        namespace: istio-system
        path: /inject
        port: 443
    failurePolicy: Fail

  public void testThreshold() throws Exception {
    testThreshold(0, 100, true, false);
    testThreshold(10, 100, true, false);
    testThreshold(100, 100, true, false);
    testThreshold(1000, 100, true, false);
    testThreshold(0, 100, false, false);
    testThreshold(10, 100, false, false);
    testThreshold(100, 100, false, false);
    testThreshold(1000, 100, false, false);
  }

		MaxIdleConnsPerHost:   maxIdleConnsPerHost,
		WriteBufferSize:       64 << 10, // 64KiB moving up from 4KiB default
		ReadBufferSize:        64 << 10, // 64KiB moving up from 4KiB default
		IdleConnTimeout:       15 * time.Second,
		ResponseHeaderTimeout: 15 * time.Minute, // Conservative timeout is the default (for MinIO internode)
		TLSHandshakeTimeout:   10 * time.Second,
		TLSClientConfig:       &tlsClientConfig,

    assertThrows(IOException.class, () -> reader.read(new char[10], 0, 10));

    assertThrows(IOException.class, () -> reader.read(CharBuffer.allocate(10)));

    assertThrows(IOException.class, () -> reader.skip(10));

    assertThrows(IOException.class, () -> reader.ready());

    assertThrows(IOException.class, () -> reader.mark(10));

    FakeTicker ticker = new FakeTicker();
    assertSame(ticker, ticker.setAutoIncrementStep(10, TimeUnit.NANOSECONDS));
  }

  public void testAutoIncrementStep_nanos() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(10, TimeUnit.NANOSECONDS);
    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {

    Count holder = new Count(20);
    assertEquals(21, holder.addAndGet(1));
  }

  public void testGetAndSet() {
    Count holder = new Count(10);
    assertEquals(10, holder.getAndSet(20));
    assertEquals(20, holder.get());
  }

  public void testSet() {
    Count holder = new Count(10);
    holder.set(20);
    assertEquals(20, holder.get());
  }

    checkArrayEquals(new String[9], ObjectArrays.newArray(new String[10], 9));
  }

  public void testNonEmptyToSameLength() {
    doTestNewArrayEquals(new String[10], 10);
  }

  public void testNonEmptyToLonger() {
    checkArrayEquals(
        new String[10], ObjectArrays.newArray(new String[] {"a", "b", "c", "d", "e"}, 10));
  }

    FakeTicker ticker = new FakeTicker();
    assertSame(ticker, ticker.setAutoIncrementStep(10, TimeUnit.NANOSECONDS));
  }

  public void testAutoIncrementStep_nanos() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(10, TimeUnit.NANOSECONDS);
    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {