}

    @Test
    void testMessageAndCauseConstructor() {
        // Test the constructor with both message and cause arguments
        String message = "Test message with cause";
        Throwable cause = new IllegalArgumentException("Invalid argument");
        RequestTimeoutException exception = new RequestTimeoutException(message, cause);
        assertEquals(message, exception.getMessage(), "Message should match the provided string");

        AvPair avPair = new AvPair(type, raw);

        assertEquals(type, avPair.getType(), "Type should match the constructor argument.");
        assertArrayEquals(raw, avPair.getRaw(), "Raw data should match the constructor argument.");

        // Test with another type and empty raw data
        int type2 = AvPair.MsvAvEOL;
        byte[] raw2 = new byte[] {};

                Arguments.of(NbtException.ERR_NAM_SRVC, NbtException.FMT_ERR, "ERR_NAM_SRVC/FMT_ERR: Format ErrorUnknown error code: 1"),
                Arguments.of(NbtException.ERR_NAM_SRVC, NbtException.SRV_ERR, "ERR_NAM_SRVC/Unknown error code: 2"),
                Arguments.of(NbtException.ERR_NAM_SRVC, NbtException.IMP_ERR, "ERR_NAM_SRVC/Unknown error code: 4"),

    }

    @Test
    void testSetMid() {
        long mid = 12345L;
        mockResponse.setMid(mid);

        // Verify that the method was called with the correct argument
        verify(mockResponse, times(1)).setMid(mid);
    }

    @Test
    void testGetMid() {
        long mid = 54321L;
        when(mockResponse.getMid()).thenReturn(mid);

   *     null} is treated as the four-character string {@code "null"}.
   * @param args the arguments to be substituted into the message template. The first argument
   *     specified is substituted for the first occurrence of {@code "%s"} in the template, and so
   *     forth. A {@code null} argument is converted to the four-character string {@code "null"};

from unicorn import UnicornMiddleware

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

`app.add_middleware()` receives a middleware class as the first argument and any additional arguments to be passed to the middleware.

## Integrated middlewares { #integrated-middlewares }

**FastAPI** includes several middlewares for common use cases, we'll see next how to use them.

### `Union` in Python 3.10 { #union-in-python-3-10 }

In this example we pass `Union[PlaneItem, CarItem]` as the value of the argument `response_model`.

Because we are passing it as a **value to an argument** instead of putting it in a **type annotation**, we have to use `Union` even in Python 3.10.

If it was in a type annotation we could have used the vertical bar, as:

```Python

   * specified accumulator function, returning the new value. The previous value associated with
   * {@code key} (or zero, if there is none) is passed as the first argument to {@code
   * accumulatorFunction}, and {@code x} is passed as the second argument.
   *
   * @since 21.0
   */
  @CanIgnoreReturnValue
  public long accumulateAndGet(K key, long x, LongBinaryOperator accumulatorFunction) {

    }

    @Nested
    @DisplayName("Argument parsing")
    class ArgumentParsing {

        @Test
        @DisplayName("URL parameter is correctly parsed")
        void urlParameterParsing() {
            String expectedUrl = "smb://server/share/test.txt";
            TestLocking t = new TestLocking();

            // Simulate argument parsing

                Arguments.of(new byte[] { (byte) 0x0F }, "0f"), Arguments.of(new byte[] { (byte) 0x10 }, "10"),
                Arguments.of(new byte[] { (byte) 0xAB }, "ab"),
                Arguments.of(new byte[] { (byte) 0x7F, (byte) 0x80, (byte) 0xFF }, "7f80ff"));
    }

    // Verifies that toString() formats bytes as lower-case hex with zero-padding
    @ParameterizedTest(name = "toString renders hex for {0}")
    @MethodSource("hexCases")