That's what makes it possible to have multiple automatic interactive documentation interfaces, code generation, etc.

OpenAPI has a way to define multiple security "schemes".

By using them, you can take advantage of all these standard-based tools, including these interactive documentation systems.

OpenAPI defines the following security schemes:

* `apiKey`: an application specific key that can come from:
    * A query parameter.
    * A header.

build:mkl --define=build_with_mkl=true --define=enable_mkl=true
build:mkl --define=tensorflow_mkldnn_contraction_kernel=0
build:mkl --define=build_with_openmp=true
build:mkl -c opt

# config to build OneDNN backend with a user specified threadpool.
build:mkl_threadpool --define=build_with_mkl=true --define=enable_mkl=true
build:mkl_threadpool --define=tensorflow_mkldnn_contraction_kernel=0

    class InterfaceMethodContractTest {

        @Test
        @DisplayName("Should define exactly four public methods")
        void shouldDefineExactlyFourPublicMethods() {
            java.lang.reflect.Method[] methods = SmbSession.class.getDeclaredMethods();
            assertEquals(4, methods.length, "SmbSession should define exactly 4 methods");
        }

        @Test

 */
@TestInstance(TestInstance.Lifecycle.PER_CLASS)
class FileInformationTest {

    /**
     * Test that interface constants are correctly defined
     */
    @Test
    @DisplayName("Test FileInformation constants are correctly defined")
    void testInterfaceConstants() {
        // Verify all constants have expected values
        assertEquals((byte) 20, FileInformation.FILE_ENDOFFILE_INFO);

# Lifespan Events { #lifespan-events }

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

* `PUT`: to update data.
* `DELETE`: to delete data.

So, in OpenAPI, each of the HTTP methods is called an "operation".

We are going to call them "**operations**" too.

#### Define a *path operation decorator* { #define-a-path-operation-decorator }

{* ../../docs_src/first_steps/tutorial001.py hl[6] *}

The `@app.get("/")` tells **FastAPI** that the function right below is in charge of handling requests that go to:

    * Because pydantic data structures are just instances of classes you define; auto-completion, linting, mypy and your intuition should all work properly with your validated data.
* Validate **complex structures**:
    * Use of hierarchical Pydantic models, Python `typing`’s `List` and `Dict`, etc.
    * And validators allow complex data schemas to be clearly and easily defined, checked and documented as JSON Schema.

/**
 * Test class for NtStatus constants
 */
@DisplayName("NtStatus Tests")
class NtStatusTest {

    @Test
    @DisplayName("Should define well-known NT status constants")
    void testWellKnownStatusConstants() {
        // Verify important NT status constants are defined
        assertEquals(0x00000000, NtStatus.NT_STATUS_SUCCESS);
        assertEquals((int) 0xC0000022L, NtStatus.NT_STATUS_ACCESS_DENIED);

**FastAPI** will know that it can use this dependency to define a "security scheme" in the OpenAPI schema (and the automatic API docs).

/// info | Technical Details

```

</div>

If you use Hypercorn, it also has the option `--root-path`.

/// note | Technical Details

The ASGI specification defines a `root_path` for this use case.

And the `--root-path` command line option provides that `root_path`.

///

### Checking the current `root_path` { #checking-the-current-root-path }