* case of (say) {@link HashSet}, which is an <i>implementation</i>, with semantics that were
 * largely defined by its supertype.
 *
 * <p>For field types and method return types, you should generally use the immutable type (such as
 * {@link ImmutableList}) instead of the general collection interface type (such as {@link List}).

     *
     * @param count number of leases to evict
     */
    private void evictOldestLeases(int count) {
        if (count <= 0 || leases.isEmpty()) {
            return;
        }

        // Find oldest leases by last access time
        leases.entrySet()
                .stream()
                .sorted((e1, e2) -> Long.compare(e1.getValue().getLastAccessTime(), e2.getValue().getLastAccessTime()))

### 创建 `Settings` 对象

从 Pydantic 导入 `BaseSettings` 并创建一个子类，与 Pydantic 模型非常相似。

与 Pydantic 模型一样，您使用类型注释声明类属性，还可以指定默认值。

您可以使用与 Pydantic 模型相同的验证功能和工具，比如不同的数据类型和使用 `Field()` 进行附加验证。

{* ../../docs_src/settings/tutorial001.py hl[2,5:8,11] *}

/// tip

如果您需要一个快速的复制粘贴示例，请不要使用此示例，而应使用下面的最后一个示例。

///

		}
	}
	return rsc.reader.Read(p)
}

// Close call to implement io.Closer. Calling Read/Seek after Close reopens the
// object for reading and a subsequent Close call is required to ensure
// resources are freed.
func (rsc *ObjectReadSeekCloser) Close() error {
	rsc.closerOnce.Do(func() {
		if rsc.reader != nil {
			rsc.closerErr = rsc.reader.Close()
			rsc.reader = nil
		}
	})
	return rsc.closerErr

    with pytest.raises(FastAPIError) as e:

        @app.get("/")
        def read_root() -> Union[Response, None]:
            return Response(content="Foo")  # pragma: no cover

    assert "valid Pydantic field type" in e.value.args[0]
    assert "parameter response_model=None" in e.value.args[0]


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text

	}

	if createdByRel, ok := userSchema.Relationships.Relations["CreatedBy"]; ok {
		if createdByRel.FieldSchema != userSchema {
			t.Fatalf("expects same field schema, but got new %p, old %p", createdByRel.FieldSchema, userSchema)
		}
	} else {
		t.Fatalf("expects created by relations, but not found")
	}
}

func TestEmbeddedHas(t *testing.T) {
	type Toy struct {

        // this can be safely acquired after the acquiredLock.
        //
        // Note that there is a race condition here which can result in missing
        // a cyclic edge: it's possible for two threads to simultaneous find
        // "safe" edges which together form a cycle. Preventing this race
        // condition efficiently without _introducing_ deadlock is probably
        // tricky. For now, just accept the race condition---missing a warning

```python
from typing import Annotated, Literal

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field

app = FastAPI()


class FilterParams(BaseModel):
    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: list[str] = []


@app.get("/items/")

class Http2Test {
  val frame = Buffer()
  val reader = Http2Reader(frame, false)
  val expectedStreamId = 15

  @Test fun unknownFrameTypeSkipped() {
    writeMedium(frame, 4) // has a 4-byte field
    frame.writeByte(99) // type 99
    frame.writeByte(FLAG_NONE)
    frame.writeInt(expectedStreamId)
    frame.writeInt(111111111) // custom data

 * @author Jon Noack
 */
@GwtIncompatible // not worth using in GWT for now
class CompactHashSet<E extends @Nullable Object> extends AbstractSet<E> implements Serializable {
  // TODO(user): cache all field accesses in local vars

  /** Creates an empty {@code CompactHashSet} instance. */
  public static <E extends @Nullable Object> CompactHashSet<E> create() {
    return new CompactHashSet<>();
  }

  /**