}

  private void doEnterScenarioSetUp() {
    switch (scenario) {
      case SATISFIED_AND_UNOCCUPIED_BEFORE_ENTERING:
        enterSatisfyGuardAndLeaveInCurrentThread();
        break;
      case UNSATISFIED_AND_UNOCCUPIED_BEFORE_ENTERING:
        break;
      case SATISFIED_AND_OCCUPIED_BEFORE_ENTERING:
        enterSatisfyGuardAndLeaveInCurrentThread();

        Operation op = operations[random.nextInt(operations.length)];
        switch (op) {
          case ADD:
            {
              int delta = random.nextInt(10);
              multiset.add(key, delta);
              deltas[keyIndex] += delta;
              break;
            }
          case SET_COUNT:
            {
              int newValue = random.nextInt(3);

            return "";
        }
        return switch (mimeType) {
        case "image/gif" -> ".gif";
        case "image/tiff" -> ".tiff";
        case "image/svg+xml" -> ".svg";
        case "image/jpeg" -> ".jpg";
        case "image/png" -> ".png";
        case "image/bmp", "image/x-windows-bmp", "image/x-ms-bmp" -> ".bmp";

      switch (input) {
        case VALID_INPUT_DATA:
          outputFuture.set(RESULT_DATA);
          break;
        case SLOW_OUTPUT_VALID_INPUT_DATA:
          break; // do nothing to the result
        case SLOW_FUNC_VALID_INPUT_DATA:
          funcIsWaitingLatch.countDown();
          awaitUninterruptibly(funcCompletionLatch);
          break;
        case EXCEPTION_DATA:
          throw EXCEPTION;
      }

      switch (input) {
        case VALID_INPUT_DATA:
          outputFuture.set(RESULT_DATA);
          break;
        case SLOW_OUTPUT_VALID_INPUT_DATA:
          break; // do nothing to the result
        case SLOW_FUNC_VALID_INPUT_DATA:
          funcIsWaitingLatch.countDown();
          awaitUninterruptibly(funcCompletionLatch);
          break;
        case EXCEPTION_DATA:
          throw EXCEPTION;
      }

## Use Case { #use-case }

Let's start with an example **use case** and then see how to solve it with this.

Let's imagine that you have some **machine learning models** that you want to use to handle requests. 🤖

## Optional parameters { #optional-parameters }

The same way, you can declare optional query parameters, by setting their default to `None`:

{* ../../docs_src/query_params/tutorial002_py310.py hl[7] *}

In this case, the function parameter `q` will be optional, and will be `None` by default.

/// check

            }
        } else {
            type = parseStorageType(typeStr);
        }

        switch (type) {
        case GCS:
            return new GcsStorageClient(fessConfig.getStorageProjectId(), bucket, endpoint, fessConfig.getStorageCredentialsPath());
        case S3:
        case S3_COMPAT:
        default:
            return new S3StorageClient(endpoint, accessKey, secretKey, bucket, fessConfig.getStorageRegion());

        final JsonToken token = jsonParser.getCurrentToken();
        return switch (token) {
        case VALUE_STRING -> jsonParser.getText();
        case VALUE_NUMBER_INT -> jsonParser.getLongValue();
        case VALUE_NUMBER_FLOAT -> jsonParser.getDoubleValue();
        case VALUE_TRUE -> true;
        case VALUE_FALSE -> false;
        case VALUE_NULL -> null;
        default -> null; // Or throw an exception if unexpected token
        };

/// tip

**GraphQL** solves some very specific use cases.

It has **advantages** and **disadvantages** when compared to common **web APIs**.

Make sure you evaluate if the **benefits** for your use case compensate the **drawbacks**. 🤓

///

## GraphQL Libraries { #graphql-libraries }

Here are some of the **GraphQL** libraries that have **ASGI** support. You could use them with **FastAPI**: