// scanning lines, a [SplitFunc] can return (0, nil, nil) to signal the
// [Scanner] to read more data into the slice and try again with a
// longer slice starting at the same point in the input.
//
// The function is never called with an empty data slice unless atEOF
// is true. If atEOF is true, however, data may be non-empty and,
// as always, holds unprocessed text.

query_extractor(["query_extractor"])
query_or_cookie_extractor(["query_or_cookie_extractor"])

read_query["/items/"]

query_extractor --> query_or_cookie_extractor --> read_query
```

## 같은 의존성을 여러 번 사용하기 { #using-the-same-dependency-multiple-times }

같은 *경로 처리*에 대해 의존성 중 하나가 여러 번 선언되는 경우(예: 여러 의존성이 공통 하위 의존성을 갖는 경우), **FastAPI**는 그 하위 의존성을 요청당 한 번만 호출해야 한다는 것을 알고 있습니다.

query_extractor(["query_extractor"])
query_or_cookie_extractor(["query_or_cookie_extractor"])

read_query["/items/"]

query_extractor --> query_or_cookie_extractor --> read_query
```

## 多次使用同一個相依項 { #using-the-same-dependency-multiple-times }

如果你的某個相依項在同一個路徑操作中被宣告了多次，例如多個相依共用同一個子相依，**FastAPI** 會知道只需在每次請求中呼叫該子相依一次。

它會把回傳值儲存在一個 <dfn title="用來儲存已計算/產生之值的工具／系統，以便重複使用而不必再次計算。">「快取」</dfn> 中，並在該次請求中傳遞給所有需要它的「相依者」，而不是為同一個請求多次呼叫相同的相依項。

 * <p>The collections created by {@link #createCollection()} may or may not allow duplicates. If the
 * collection, such as a {@link Set}, does not support duplicates, an added key-value pair will
 * replace an existing pair with the same key and value, if such a pair is present. With collections
 * like {@link List} that allow duplicates, the collection will keep the existing key-value pairs
 * while adding a new pair.
 *

        SmbTreeHandleInternal t2 = handle.ensureTreeConnected();

        // Assert
        assertSame(tree, t1, "First acquire returns provided tree");
        assertSame(tree, t2, "Subsequent acquire returns same tree instance");
        verify(pipe, times(1)).ensureTreeConnected();
        verify(tree, times(2)).acquire();
    }

    @Test
    @DisplayName("getInput/getOutput return cached streams when open; throw when closed")

   *
   * <p>If {@link ByteSource#asCharSource} is called on the returned source with the same charset,
   * the default implementation of this method will ensure that the original {@code CharSource} is
   * returned, rather than round-trip encoding. Subclasses that override this method should behave
   * the same way.
   *
   * @since 20.0
   */
  public ByteSource asByteSource(Charset charset) {

  @SuppressWarnings("InlineMeInliner")
  public void testCompare() {
    for (int x : VALUES) {
      for (int y : VALUES) {
        // note: spec requires only that the sign is the same
        assertWithMessage("%s, %s", x, y).that(Ints.compare(x, y)).isEqualTo(Integer.compare(x, y));
      }
    }
  }

  public void testContains() {
    assertThat(Ints.contains(EMPTY, (int) 1)).isFalse();

        Set<ConstraintViolation<ExtendedTestBean>> violations = validator.validate(bean);
        assertEquals(2, violations.size());
    }

    // Test multiple annotations on same field
    @Test
    public void test_multipleValidations() {
        MultiValidationBean bean = new MultiValidationBean();
        bean.setRequiredCron(null); // Violates NotNull

  /**
   * Records an exception so that it can be rethrown later in the test harness thread, triggering a
   * test case failure. Only the first failure is recorded; subsequent calls to this method from
   * within the same test have no effect.
   */
  final void threadRecordFailure(Throwable t) {
    threadFailure.compareAndSet(null, t);
  }

  /**
   * Extra checks that get done for all test cases.
   *

         * that chained message. Before doing so we must increment
         * the batchLevel of the andx message in case it itself is an
         * andx message and needs to perform the same check as above.
         */

        andx.batchLevel = batchLevel + 1;

        dst[start + ANDX_COMMAND_OFFSET] = andxCommand;
        dst[start + ANDX_RESERVED_OFFSET] = (byte) 0x00;