sequenceDiagram
    participant App
    participant Client

    App->>App: Produce Item 1
    App->>Client: Send Item 1
    App->>App: Produce Item 2
    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...
```

///

## 嵌入單一 Body 參數 { #embed-a-single-body-parameter }

假設你只有一個來自 Pydantic 模型 `Item` 的單一 `item` Body 參數。

預設情況下，**FastAPI** 會直接期望該模型的內容作為請求主體。

但如果你想讓它像宣告多個 Body 參數時那樣，期望一個帶有 `item` 鍵、其內含模型內容的 JSON，你可以使用 `Body` 的特殊參數 `embed`：

```Python
item: Item = Body(embed=True)
```

如下：

{* ../../docs_src/body_multiple_params/tutorial005_an_py310.py hl[17] *}

from fastapi import FastAPI
from pydantic import BaseModel


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


app = FastAPI()


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item):

                            },
                        },
                        "summary": "Read Item",
                        "operationId": "read_item_items__item_id__get",
                        "parameters": [
                            {
                                "required": True,
                                "schema": {"title": "Item Id", "type": "string"},
                                "name": "item_id",

            }

            private String getFromCache(final String propertyKey) {
                try {
                    return cache.get(propertyKey, () -> {
                        final String value = System.getProperty(Constants.FESS_CONFIG_PREFIX + propertyKey, super.get(propertyKey));
                        if (value == null) {
                            throw new KeyNotFoundException(propertyKey);
                        }

    /**
     * {@inheritDoc}
     *
     * @see jcifs.Encodable#encode(byte[], int)
     */
    @Override
    public int encode(final byte[] dst, int dstIndex) {
        final int start = dstIndex;

        System.arraycopy(this.sourceKey, 0, dst, dstIndex, 24);
        dstIndex += 24;

        SMBUtil.writeInt4(this.chunks.length, dst, dstIndex);
        dstIndex += 4;

        dstIndex += 4; // Reserved

                            },
                            "200": {
                                "description": "Item requested by ID",
                                "content": {
                                    "application/json": {
                                        "schema": {"$ref": "#/components/schemas/Item"},
                                        "example": {
                                            "id": "bar",

sequenceDiagram
    participant App
    participant Client

    App->>App: Produce Item 1
    App->>Client: Send Item 1
    App->>App: Produce Item 2
    Client->>Client: Process Item 1
    App->>Client: Send Item 2
    App->>App: Produce Item 3
    Client->>Client: Process Item 2
    App->>Client: Send Item 3
    Client->>Client: Process Item 3
    Note over App: Keeps producing...
    Note over Client: Keeps consuming...
```

        file("src/test/java/acme/SomeTests.java").text = """

        public class SomeTests {
            @org.junit.Test
            public void testSysInput() {
                org.junit.Assert.assertEquals("bar", System.getProperty("foo"));
            }
        }

        """
        buildFile.text = """
            plugins {
             id 'java'
             id 'elasticsearch.test-base'
            }

    }

    /**
     * Checks if the item has been updated.
     *
     * @return true if the item has been updated, false otherwise.
     */
    public boolean isUpdated() {
        return newInputs != null && newOutputs != null;
    }

    /**
     * Checks if the item has been marked for deletion.
     *
     * @return true if the item is marked for deletion, false otherwise.
     */