例如，假設你定義了一個「路徑操作（path operation）」`/items/`：

{* ../../docs_src/behind_a_proxy/tutorial001_01_py310.py hl[6] *}

如果用戶端嘗試前往 `/items`，預設會被重新導向到 `/items/`。

但在設定「CLI 選項」`--forwarded-allow-ips` 之前，它可能會被重新導向到 `http://localhost:8000/items/`。

不過，也許你的應用實際部署在 `https://mysuperapp.com`，那重新導向就應該是 `https://mysuperapp.com/items/`。

設定 `--proxy-headers` 之後，FastAPI 就能重新導向到正確的位置。😎

```
https://mysuperapp.com/items/
```

/// tip

    // Test preconditions
    assertThrows(IllegalArgumentException.class, () -> source.slice(-1, 10));

    assertThrows(IllegalArgumentException.class, () -> source.slice(0, -1));

    assertCorrectSlice(0, 0, 0, 0);
    assertCorrectSlice(0, 0, 1, 0);
    assertCorrectSlice(100, 0, 10, 10);
    assertCorrectSlice(100, 0, 100, 100);
    assertCorrectSlice(100, 5, 10, 10);
    assertCorrectSlice(100, 5, 100, 95);

  if (decoded != normalizeNfc(decoded)) return null

  // TODO: Must not begin with a combining mark.
  // TODO: Each character must be 'valid' or 'deviation'. Not mapped.
  // TODO: CheckJoiners from IDNA 2008
  // TODO: CheckBidi from IDNA 2008, RFC 5893, Section 2.

  return Punycode.encode(decoded)

    private final int maxAnalyzedContentLength;

    /**
     * Constructor.
     */
    public DefaultContentsParser() {
        maxAnalyzedContentLength = Integer.getInteger("fess.suggest.max.analyzed.content.length", 1000);
    }

    @Override
    public SuggestItem parseSearchWords(final String[] words, final String[][] readings, final String[] fields, final String[] tags,

    /**
     * Test isSearchField() performance with large field set.
     */
    @Test
    public void test_isSearchField_performance() {
        // Create a large set of search fields
        int fieldCount = 1000;
        String[] fields = new String[fieldCount];
        for (int i = 0; i < fieldCount; i++) {
            fields[i] = "field" + i;
        }
        queryFieldConfig.setSearchFields(fields);

        assertSame(specificHandle, handleField.get(lookupSids));
    }

    @Test
    void constructor_shouldHandleLargeSidArray() {
        // Arrange
        int largeSize = 1000;
        testSids = new jcifs.SID[largeSize];
        for (int i = 0; i < largeSize; i++) {
            testSids[i] = mock(jcifs.SID.class);
            when(testSids[i].unwrap(sid_t.class)).thenReturn(mockSidT);

        // Arrange
        transPeekNamedPipe = new TransPeekNamedPipe(mockConfig, TEST_PIPE_NAME, TEST_FID);
        byte[] smallBuffer = new byte[1];
        byte[] largeBuffer = new byte[1000];

        // Act & Assert
        assertEquals(0, transPeekNamedPipe.readSetupWireFormat(smallBuffer, 0, 1));
        assertEquals(0, transPeekNamedPipe.readSetupWireFormat(largeBuffer, 500, 500));

        long endTime = System.currentTimeMillis();
        long duration = endTime - startTime;

        // Then - should complete quickly (this is more of a performance indicator)
        assertTrue(duration < 1000, "Creating and using 10000 EmptyIterators should be fast (took " + duration + "ms)");
    }

    @Test
    @DisplayName("EmptyIterator should work correctly in nested iteration")
    void testNestedIteration() {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(baos);

        // Write a RID (4 bytes) for readId() method
        writeLittleEndianInt(dos, 1000);

        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
        PacDataInputStream pacStream = new PacDataInputStream(bais);

        SID id = pacStream.readId();

        refresh();
    }

    @AfterAll
    protected static void tearDownAll() {
        // Clean up failure URL logs
        final Map<String, Object> requestBody = new HashMap<>();
        requestBody.put("size", 1000);
        checkMethodBase(requestBody).delete(API_PATH + "/all");
        refresh();

        // Clean up job logs
        final List<Map<String, Object>> jobLogList = readJobLog(NAME_PREFIX);