///

## 声明模型属性 { #declare-model-attributes }

然后，使用 `Field` 定义模型的属性：

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[11:14] *}

`Field` 的工作方式和 `Query`、`Path`、`Body` 相同，参数也相同。

/// note | 技术细节

实际上，`Query`、`Path` 以及你接下来会看到的其它对象，会创建公共 `Param` 类的子类的对象，而 `Param` 本身是 Pydantic 中 `FieldInfo` 的子类。

Pydantic 的 `Field` 返回也是 `FieldInfo` 的类实例。

`Body` 直接返回的也是 `FieldInfo` 的子类的对象。后文还会介绍一些 `Body` 的子类。

			return true
		}
		x[t.Key] = struct{}{}
	}

	return false
}

// BySize returns true when sz satisfies a
// ObjectSizeLessThan/ObjectSizeGreaterthan or a logical AND of these predicates
// Note: And combines size and other predicates like Tags, Prefix, etc. This
// method applies exclusively to size predicates only.
func (a And) BySize(sz int64) bool {
	if a.ObjectSizeGreaterThan > 0 &&
		sz <= a.ObjectSizeGreaterThan {

 *     String name = header.getName();
 *     String value = header.getValue();
 *     boolean isValid = header.isValid();
 * </pre>
 *
 * <p>Note: The name should not be blank and the value should not be null for the header to be considered valid.</p>
 *
 * @see java.io.Serializable
 */
public class RequestHeader implements Serializable {

    putEdge(N1, N1);
    assertThat(graph.outDegree(N1)).isEqualTo(2);
    putEdge(N2, N1);
    assertThat(graph.outDegree(N1)).isEqualTo(3);
  }

  // Stable order tests

  // Note: Stable order means that the ordering doesn't change between iterations and versions.
  // Ideally, the ordering in test should never be updated.
  @Test
  public void stableIncidentEdgeOrder_edges_returnsInStableOrder() {

**FastAPI** 会获取该模型，生成它的 JSON Schema，并将其放在 OpenAPI 中的正确位置。

例如，要声明另一个状态码为 `404` 且具有 Pydantic 模型 `Message` 的响应，你可以这样写：

{* ../../docs_src/additional_responses/tutorial001_py310.py hl[18,22] *}

/// note | 注意

记住你需要直接返回 `JSONResponse`。

///

/// info | 信息

`model` 键不是 OpenAPI 的一部分。

**FastAPI** 会从这里获取 Pydantic 模型，生成 JSON Schema，并把它放到正确的位置。

正确的位置是：

        } catch (final NoSuchMethodException e) {
            fail("Constructor with Context parameter should exist");
        }
    }

    // Note: This test is simplified because complex Tomcat Context mocking
    // is difficult to maintain due to frequent API changes.
    // The focus is on testing the class structure and basic functionality

variable. Use `idevice_id -l` to list all available UDIDs. Then, setting GOARCH to arm64
will select the device:

	GOOS=ios GOARCH=arm64 CGO_ENABLED=1 CC_FOR_TARGET=$(pwd)/../misc/ios/clangwrap.sh ./all.bash

Note that the go_darwin_$GOARCH_exec wrapper uninstalls any existing app identified by
the bundle id before installing a new app. If the uninstalled app is the last app by

        },
        (Multiset<E> multiset) -> copyOfSortedEntries(comparator, multiset.entrySet()));
  }

  /**
   * Returns the empty immutable sorted multiset.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")
  public static <E> ImmutableSortedMultiset<E> of() {

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static java.util.Objects.requireNonNull;

/**
 * <p>
 * Calculates the task segments in the build
 * </p>
 * <strong>NOTE:</strong> This class is not part of any public api and can be changed or deleted without prior notice.
 *
 * @since 3.0
 */
@Named
@Singleton

            }

            if (plugins.size() != normalized.size()) {
                build.setPlugins(new ArrayList<>(normalized.values()));
            }
        }

        /*
         * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that dependencies are
         * unique within a single POM. Upon multiple declarations, 2.x just kept the last one but retained the order of