When marshaling, a struct field with the new `omitzero` option in the struct field
tag will be omitted if its value is zero. If the field type has an `IsZero() bool`
method, that will be used to determine whether the value is zero. Otherwise, the
value is zero if it is [the zero value for its type](/ref/spec#The_zero_value).

If both `omitempty` and `omitzero` are specified, the field will be omitted if the

# 请求体 - 更新数据

## 用 `PUT` 更新数据

更新数据请用 <a href="https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Methods/PUT" class="external-link" target="_blank">HTTP `PUT`</a> 操作。

把输入数据转换为以 JSON 格式存储的数据（比如，使用 NoSQL 数据库时），可以使用 `jsonable_encoder`。例如，把 `datetime` 转换为 `str`。

```Python hl_lines="30-35"
{!../../docs_src/body_updates/tutorial001.py!}
```

`PUT` 用于接收替换现有数据的数据。

### 关于更新数据的警告

用 `PUT` 把数据项 `bar` 更新为以下内容时：

```Python
{

      @Require(absent = FOO)
      public void test() {}
    }

    Method method = Tester.class.getMethod("test");
    ConflictingRequirementsException e =
        assertThrows(ConflictingRequirementsException.class, () -> buildTesterRequirements(method));
    assertThat(e.getConflicts()).containsExactly(FOO);
    assertThat(e.getSource()).isEqualTo(method);
  }

  public void testBuildDeclaredTesterRequirements() throws Exception {

 * IteratorTester#newTargetIterator()} method. This is because it's impossible to test an Iterator
 * without changing its state, so the tester needs a steady supply of fresh Iterators.
 *
 * <p>If your iterator supports modification through {@code remove()}, you may wish to override the
 * verify() method, which is called after each sequence and is guaranteed to be called

    assertEquals(0xBEBAFECA, Float.floatToIntBits(in.readFloat()));
    assertEquals(0xBEBAFECAEFBEADDEL, Double.doubleToLongBits(in.readDouble()));
  }

  @SuppressWarnings("deprecation") // testing a deprecated method
  public void testWriteBytes() throws IOException {

    /* Write out various test values in LITTLE ENDIAN FORMAT */
    out.writeBytes("r\u00C9sum\u00C9");

    byte[] data = baos.toByteArray();

    assertEquals(0xBEBAFECA, Float.floatToIntBits(in.readFloat()));
    assertEquals(0xBEBAFECAEFBEADDEL, Double.doubleToLongBits(in.readDouble()));
  }

  @SuppressWarnings("deprecation") // testing a deprecated method
  public void testWriteBytes() throws IOException {

    /* Write out various test values in LITTLE ENDIAN FORMAT */
    out.writeBytes("r\u00C9sum\u00C9");

    byte[] data = baos.toByteArray();

     * not in {@link #nextElements}, this method throws an {@link UnknownElementException}.
     *
     * <p>This method is used when testing iterators without a known ordering. We poll the target
     * iterator's next element and pass it to the reference iterator through this method so it can
     * return the same element. This enables the assertion to pass and the reference iterator to

        .build(),
    )
    val response = client.newCall(request().build()).execute()
    assertThat(response.body).isNotNull()
    response.body.bytes()
    logRecorder
      .assertLogMatch(Regex("""callStart: Request\{method=GET, url=$url\}"""))
      .assertLogMatch(Regex("""proxySelectStart: $url"""))
      .assertLogMatch(Regex("""proxySelectEnd: \[DIRECT]"""))
      .assertLogMatch(Regex("""dnsStart: ${url.host}"""))

/**
 * Standard implementation of {@link MutableGraph} that supports both directed and undirected
 * graphs. Instances of this class should be constructed with {@link GraphBuilder}.
 *
 * <p>Time complexities for mutation methods are all O(1) except for {@code removeNode(N node)},
 * which is in O(d_node) where d_node is the degree of {@code node}.
 *
 * @author James Sexton
 * @param <N> Node parameter type
 */
@ElementTypesAreNonnullByDefault

 * java.util.concurrent.atomic} package specification for description of the properties of atomic
 * variables.
 *
 * <p><a id="bitEquals"></a>This class compares primitive {@code double} values in methods such as
 * {@link #compareAndSet} by comparing their bitwise representation using {@link
 * Double#doubleToRawLongBits}, which differs from both the primitive double {@code ==} operator and