* Если это не так, клиент увидит полезную понятную ошибку.
* Проверять, есть ли необязательный параметр запроса с именем `q` (например, `http://127.0.0.1:8000/items/foo?q=somequery`) для `GET` HTTP-запросов.
    * Поскольку параметр `q` объявлен с `= None`, он необязателен.
    * Без `None` он был бы обязательным (как тело запроса в случае с `PUT`).

flowers

// fly : Charleston Road Registry Inc.
// https://www.iana.org/domains/root/db/fly.html
fly

// foo : Charleston Road Registry Inc.
// https://www.iana.org/domains/root/db/foo.html
foo

// food : Internet Naming Company LLC
// https://www.iana.org/domains/root/db/food.html
food

// football : Binky Moon, LLC
// https://www.iana.org/domains/root/db/football.html
football

    * Si ce n'est pas le cas, le client verra une erreur utile et claire.
* Vérifier s'il existe un paramètre de requête optionnel nommé `q` (comme dans `http://127.0.0.1:8000/items/foo?q=somequery`) pour les requêtes `GET`.
    * Comme le paramètre `q` est déclaré avec `= None`, il est optionnel.
    * Sans le `None`, il serait requis (comme l'est le corps dans le cas de `PUT`).

     */
    public final CharSource asCharSource(Charset charset) {
      return Resources.asCharSource(url(), charset);
    }

    /** Returns the fully qualified name of the resource. Such as "com/mycomp/foo/bar.txt". */
    public final String getResourceName() {
      return resourceName;
    }

    /** Returns the file that includes this resource. */
    final File getFile() {
      return file;
    }

* Validate that the `item_id` is of type `int` for `GET` and `PUT` requests.
    * If it is not, the client will see a useful, clear error.
* Check if there is an optional query parameter named `q` (as in `http://127.0.0.1:8000/items/foo?q=somequery`) for `GET` requests.
    * As the `q` parameter is declared with `= None`, it is optional.
    * Without the `None` it would be required (as is the body in the case with `PUT`).

---

回到前面的程式碼範例，**FastAPI** 會：

* 驗證 `GET` 與 `PUT` 請求的路徑中是否包含 `item_id`。
* 驗證 `GET` 與 `PUT` 請求中的 `item_id` 是否為 `int` 型別。
    * 如果不是，客戶端會看到清楚有用的錯誤。
* 在 `GET` 請求中檢查是否有名為 `q` 的可選查詢參數（如 `http://127.0.0.1:8000/items/foo?q=somequery`）。
    * 因為 `q` 參數被宣告為 `= None`，所以它是可選的。
    * 若沒有 `None`，則它會是必填（就像 `PUT` 時的 body）。
* 對於 `/items/{item_id}` 的 `PUT` 請求，以 JSON 讀取 body：
    * 檢查是否有必填屬性 `name`，且為 `str`。
    * 檢查是否有必填屬性 `price`，且為 `float`。

An error on not-declared:1 indicates that foo is undeclared.
An error on not-type:1 indicates that foo is not a type (if declared at all, it is an identifier).
An error on not-int-const:1 indicates that foo is not an integer constant.
An error on not-num-const:1 indicates that foo is not a number constant.
An error on not-str-lit:1 indicates that foo is not a string literal.
An error on not-signed-int-const:1 indicates that foo is not a signed integer constant.

        // To align Maven with outcomes, we set here color enabled based on these premises.
        // Note: Maven3 suffers from similar thing: if you do `mvn3 foo > log.txt`, the output will
        // not be not colored (good), but Maven will print out "Message scheme: color".
        MessageUtils.setColorEnabled(

                </div>
            </la:form>
        </section>
    </main>
    <jsp:include page="/WEB-INF/view/common/admin/footer.jsp"></jsp:include>
</div>
<jsp:include page="/WEB-INF/view/common/admin/foot.jsp"></jsp:include>
</body>

			recordDelimiter: "\n",
			fieldDelimiter:  ",",
			sendErr:         nil,
			header:          true,
			wantColumns:     []string{"header1", "header2", "header3"},
			wantFields:      "ok1,ok2,ok3\n" + `"foo""bar"` + "\n",
			wantErr:         io.EOF,
		},
		{
			// This works since LazyQuotes is true:
			file:            "invalid-csv.csv",
			recordDelimiter: "\n",
			fieldDelimiter:  ",",