```

### More technical details { #more-technical-details }

You might have noticed that `await` can only be used inside of functions defined with `async def`.

But at the same time, functions defined with `async def` have to be "awaited". So, functions with `async def` can only be called inside of functions defined with `async def` too.

So, about the egg and the chicken, how do you call the first `async` function?

import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.SortedSet;
import org.jspecify.annotations.Nullable;

/**
 * A range (or "interval") defines the <i>boundaries</i> around a contiguous span of values of some
 * {@code Comparable} type; for example, "integers from 1 to 100 inclusive." Note that it is not

    // vol. 2, Knuth, 4.2.2, (16) to the two-variable case. We have two value series x_i and y_i.
    // We define the arithmetic means X_n = 1/n \sum_{i=1}^n x_i, and Y_n = 1/n \sum_{i=1}^n y_i.
    // We also define the sum of the products of the differences from the means
    //           C_n = \sum_{i=1}^n x_i y_i - n X_n Y_n
    // for all n >= 1. Then for all n > 1:

    @Nonnull
    RequestType getRequestType();

    boolean isLocationTracking();

    boolean isRecursive();

    /**
     * Defines external profiles that may be activated for the given model.
     * Those are external profiles usually defined in {@link org.apache.maven.api.settings.Settings#getProfiles()}.
     */
    @Nonnull
    Collection<Profile> getProfiles();

    /**

You will also get autocompletion for the payload to send:

<img src="/img/tutorial/generate-clients/image03.png">

/// tip

Notice the autocompletion for `name` and `price`, that was defined in the FastAPI application, in the `Item` model.

///

You will have inline errors for the data that you send:

<img src="/img/tutorial/generate-clients/image04.png">

  public static final MediaType WEBM_AUDIO = createConstant(AUDIO_TYPE, "webm");

  /**
   * L16 audio, as defined by <a href="https://tools.ietf.org/html/rfc2586">RFC 2586</a>.
   *
   * @since 24.1
   */
  public static final MediaType L16_AUDIO = createConstant(AUDIO_TYPE, "l16");

  /**
   * L24 audio, as defined by <a href="https://tools.ietf.org/html/rfc3190">RFC 3190</a>.
   *
   * @since 20.0
   */

-}} {{/* Determine name for scc role and rolebinding */}} {{- define "minio.sccRoleName" -}} {{- printf "%s-%s" "scc" (include "minio.fullname" .) | trunc 63 | trimSuffix "-" -}} {{- end -}} {{/* Properly format optional additional arguments to MinIO binary */}} {{- define "minio.extraArgs" -}} {{- range .Values.extraArgs -}} {{ " " }}{{ . }} {{- end -}} {{- end -}} {{/* Return the proper Docker Image Registry Secret Names */}} {{- define "minio.imagePullSecrets" -}} {{/* Helm 2.11 supports the assignment...

-}} {{/* Determine name for scc role and rolebinding */}} {{- define "minio.sccRoleName" -}} {{- printf "%s-%s" "scc" (include "minio.fullname" .) | trunc 63 | trimSuffix "-" -}} {{- end -}} {{/* Properly format optional additional arguments to MinIO binary */}} {{- define "minio.extraArgs" -}} {{- range .Values.extraArgs -}} {{ " " }}{{ . }} {{- end -}} {{- end -}} {{/* Return the proper Docker Image Registry Secret Names */}} {{- define "minio.imagePullSecrets" -}} {{/* Helm 2.11 supports the assignment...

///

## OAuth2 scopes and OpenAPI { #oauth2-scopes-and-openapi }

The OAuth2 specification defines "scopes" as a list of strings separated by spaces.

The content of each of these strings can have any format, but should not contain spaces.

These scopes represent "permissions".

In OpenAPI (e.g. the API docs), you can define "security schemes".

When one of these security schemes uses OAuth2, you can also declare and use scopes.

But it was created before there existed Python type hints. So, to define every <dfn title="the definition of how data should be formed">schema</dfn> you need to use specific utils and classes provided by Marshmallow.

/// check | Inspired **FastAPI** to

Use code to define "schemas" that provide data types and validation, automatically.

///