If one of your dependencies is declared multiple times for the same *path operation*, for example, multiple dependencies have a common sub-dependency, **FastAPI** will know to call that sub-dependency only once per request.

    long startTime = ticker.read();
    V calculatedValue;
    try {
      calculatedValue = checkNotNull(loader).load(key);
      // TODO(b/147136275): Perform the null check on the result before the put() call.
      put(key, calculatedValue);
    } catch (RuntimeException e) {
      statsCounter.recordLoadException(ticker.read() - startTime);
      throw new UncheckedExecutionException(e);
    } catch (Exception e) {

// If some data is available but not len(p) bytes, Read conventionally returns what is available instead of waiting for more.
// When Read encounters an error or end-of-file condition after successfully reading n > 0 bytes, it returns the number of bytes read.
// It may return the (non-nil) error from the same call or return the error (and n == 0) from a subsequent call.

    int NT_STATUS_MORE_PROCESSING_REQUIRED = 0xC0000016;
    /** Access is denied */
    int NT_STATUS_ACCESS_DENIED = 0xC0000022;
    /** The data area passed to a system call is too small */
    int NT_STATUS_BUFFER_TOO_SMALL = 0xC0000023;
    /** The object name is invalid */
    int NT_STATUS_OBJECT_NAME_INVALID = 0xC0000033;
    /** The object was not found */

// or a function call.
type PrimaryTerm struct {
	Value         *LitValue   `parser:"  @@"`
	JPathExpr     *JSONPath   `parser:"| @@"`
	ListExpr      *ListExpr   `parser:"| @@"`
	SubExpression *Expression `parser:"| \"(\" @@ \")\""`
	// Include function expressions here.
	FuncCall *FuncExpr `parser:"| @@"`
}

// FuncExpr represents a function call
type FuncExpr struct {

            fail("Constructor with Context parameter should exist");
        }
    }

    @Test
    public void test_methodsExist() {
        // Verify that processWebInfLib method is overridden (it's protected so we can't call it directly)
        try {
            final java.lang.reflect.Method method = FessWebResourceRoot.class.getDeclaredMethod("processWebInfLib");
            assertNotNull(method, "processWebInfLib method should exist");

import okhttp3.internal.toHostHeader
import okio.GzipSource
import okio.buffer

/**
 * Bridges from application code to network code. First it builds a network request from a user
 * request. Then it proceeds to call the network. Finally it builds a user response from the network
 * response.
 */
class BridgeInterceptor : Interceptor {
  @Throws(IOException::class)
  override fun intercept(chain: Interceptor.Chain): Response {

        listener.transferInitiated(event(session, resource, TransferEvent.EventType.INITIATED));

        Thread.sleep(500); // to make sure queue is processed, cancellation applied

        // subsequent call will cancel
        assertThrows(
                TransferCancelledException.class,
                () -> listener.transferStarted(event(session, resource, TransferEvent.EventType.STARTED)));
    }

    @Test

# 偵錯 { #debugging }

你可以在編輯器中連接偵錯器，例如 Visual Studio Code 或 PyCharm。

## 呼叫 `uvicorn` { #call-uvicorn }

在你的 FastAPI 應用程式中，直接匯入並執行 `uvicorn`：

{* ../../docs_src/debugging/tutorial001_py310.py hl[1,15] *}

### 關於 `__name__ == "__main__"` { #about-name-main }

`__name__ == "__main__"` 的主要目的是，當你的檔案以以下方式呼叫時，執行某些程式碼：

<div class="termy">

```console
$ python myapp.py
```

</div>

但當其他檔案匯入它時不會執行，例如：

```Python

   * href="https://docs.oracle.com/javase/tutorial/java/generics/genTypeInference.html#type-inference-instantiation">"diamond"
   * syntax</a>.
   */
  @SuppressWarnings("NonApiType") // acts as a direct substitute for a constructor call
  public static <E extends @Nullable Object> HashSet<E> newHashSet() {
    return new HashSet<>();
  }

  /**
   * Creates a <i>mutable</i> {@code HashSet} instance initially containing the given elements.
   *