suite.addTestSuite(SafeTreeSetTest.class);
    suite.addTest(
        NavigableSetTestSuiteBuilder.using(
                new TestStringSetGenerator() {
                  @Override
                  protected Set<String> create(String[] elements) {
                    return new SafeTreeSet<>(asList(elements));
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {

    suite.addTest(
        CollectionTestSuiteBuilder.using(
                new TestStringCollectionGenerator() {
                  @Override
                  protected Collection<String> create(String[] elements) {
                    return new StandardImplForwardingCollection<>(
                        new LinkedList<>(asList(elements)));
                  }
                })

### Top-level application { #top-level-application }

First, create the main, top-level, **FastAPI** application, and its *path operations*:

{* ../../docs_src/sub_applications/tutorial001_py310.py hl[3, 6:8] *}

### Sub-application { #sub-application }

Then, create your sub-application, and its *path operations*.

    ) {
        Project project = createProject(bwcVersions);
        Project archiveProject = ProjectBuilder.builder().withParent(bwcProject).withName(projectName).build();
        archiveProject.getConfigurations().create(config);
        archiveProject.getArtifacts().add(config, new File("doesnotmatter"));
        createDistro(project, "distro", version.toString(), type, platform, true);
    }

 * objects and provides methods to begin tracking, record events, and
 * finalize statistics collection.
 *
 */
public class CrawlerStatsHelper {

    /**
     * Creates a new instance of CrawlerStatsHelper.
     */
    public CrawlerStatsHelper() {
        // Default constructor
    }

    /** Logger instance for this class. */

    /**
     * The underlying UUID representing this handle GUID
     */
    private final UUID guid;

    /**
     * Create a new random handle GUID
     */
    public HandleGuid() {
        this.guid = UUID.randomUUID();
    }

    /**
     * Create a handle GUID from existing bytes
     * @param bytes the 16-byte GUID data in little-endian format (SMB wire format)
     */

# Sub-dependencies { #sub-dependencies }

You can create dependencies that have **sub-dependencies**.

They can be as **deep** as you need them to be.

**FastAPI** will take care of solving them.

## First dependency "dependable" { #first-dependency-dependable }

You could create a first dependency ("dependable") like:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

<div class="termy">

```console
$ pip install sqlmodel
---> 100%
```

</div>

## 创建含有单一模型的应用 { #create-the-app-with-a-single-model }

我们先创建应用的最简单的第一个版本，只有一个 **SQLModel** 模型。

稍后我们将通过下面的**多个模型**提高其安全性和多功能性。🤓

### 创建模型 { #create-models }

导入 `SQLModel` 并创建一个数据库模型：

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[1:11] hl[7:11] *}

        if (b != null) {
            def = b.toLowerCase().equals("true");
        }
        return def;
    }

    /**
     * Retrieve an array of <code>InetAddress</code> created from a property
     * value containting a <code>delim</code> separated list of hostnames and/or
     * ipaddresses.
     *
     * @param key the property key to look up

     */
    protected volatile boolean isInit = false;

    /**
     * The GCS Storage client instance for interacting with Google Cloud Storage.
     */
    protected Storage storage;

    /**
     * Creates a new GcsClient instance.
     */
    public GcsClient() {
        super();
    }

    @Override
    public synchronized void init() {
        if (isInit) {
            return;
        }