return elements[index];
                  }
                };
              }
            })
        .named("AbstractList")
        .withFeatures(
            CollectionFeature.NONE, CollectionFeature.ALLOWS_NULL_VALUES, CollectionSize.ANY)
        .suppressing(suppressForAbstractList())
        .createTestSuite();
  }

  public Test testsForAbstractSequentialList() {

                    return elements[index];
                  }
                };
              }
            })
        .named("AbstractList")
        .withFeatures(
            CollectionFeature.NONE, CollectionFeature.ALLOWS_NULL_VALUES, CollectionSize.ANY)
        .suppressing(suppressForAbstractList())
        .createTestSuite();
  }

  public Test testsForAbstractSequentialList() {

Bu, **FastAPI**’nin bir kısıtı değildir; HTTP protocol’ünün bir parçasıdır.

///

## Opsiyonel Dosya Upload { #optional-file-upload }

Standart type annotation’ları kullanıp varsayılan değeri `None` yaparak bir dosyayı opsiyonel hale getirebilirsiniz:

{* ../../docs_src/request_files/tutorial001_02_an_py310.py hl[9,17] *}

## Ek Metadata ile `UploadFile` { #uploadfile-with-additional-metadata }

                    }
                    this.sids[_i].decode(_src);
                }
            }
        }
    }

    /** SID name type: none. */
    /** SID name type: none or unused. */
    public static final int SID_NAME_USE_NONE = 0;
    /** SID name type: user. */
    /** SID name type: user account. */
    public static final int SID_NAME_USER = 1;

```Python
from typing import Union
from fastapi import Cookie, FastAPI, Header, Path, Query

app = FastAPI()


@app.get("/items/{item_id}")
def main(
    item_id: int = Path(gt=0),
    query: Union[str, None] = Query(default=None, max_length=10),
    session: Union[str, None] = Cookie(default=None, min_length=3),

            Files.deleteIfExists(tempFile);
        }
    }

    @Test
    public void test_deleteIfExists_nonExistingFile() throws Exception {
        // Test that Files.deleteIfExists doesn't throw on non-existing file
        Path tempDir = Files.createTempDirectory("toctou_test");
        try {
            Path nonExistingFile = tempDir.resolve("non_existing.tmp");
            assertFalse(Files.exists(nonExistingFile));

  }

  static <E extends @Nullable Object> Set<E> newConcurrentHashSet() {
    // GWT's ConcurrentHashMap is a wrapper around HashMap, but it rejects null keys, which matches
    // the behaviour of the non-GWT implementation of newConcurrentHashSet().
    // On the other hand HashSet might be better for code size if apps aren't
    // already using Collections.newSetFromMap and ConcurrentHashMap.

        // Act
        int actual = findNtStatusOrMinusOne(dosCode);

        // Assert
        assertEquals(-1, actual);
    }

    @Test
    @DisplayName("Structure: DOS_ERROR_CODES is non-null with [code,status] pairs")
    void dosErrorCodesStructureIsValid() {
        // Arrange & Act
        int[][] table = DosError.DOS_ERROR_CODES;

        // Assert

        assertTrue(exception.getMessage().length() > 0);
    }

    @Test
    @DisplayName("Should check if exception is retriable")
    void testRetriableExceptions() {
        // Test non-retriable errors
        SmbException accessDenied = new SmbException(NtStatus.NT_STATUS_ACCESS_DENIED, false);
        // Note: isRetriable() method does not exist in SmbException
        assertNotNull(accessDenied);

/// tip | Порада

Оскільки Pydantic серіалізує це на боці **Rust**, ви отримаєте значно вищу **продуктивність**, ніж якби не оголошували тип повернення.

///

### Не-async *функції операцій шляху* { #non-async-path-operation-functions }

Ви також можете використовувати звичайні функції `def` (без `async`) і використовувати `yield` так само.

FastAPI подбає про коректне виконання, щоб воно не блокувало цикл подій.