start = System.currentTimeMillis();
        SerializeUtil.serialize(hmap);
        System.out.println("HashMap serialize:" + (System.currentTimeMillis() - start));

        start = System.currentTimeMillis();
        SerializeUtil.serialize(amap);
        System.out.println("ArrayMap serialize:" + (System.currentTimeMillis() - start));
    }

    private static class MyKey {

    }

    /**
     * Serialize the inbound Model instance to a StringWriter, perform the regex replacement to resolve
     * POM expressions, then re-parse into the resolved Model instance.
     * <p>
     * <b>NOTE:</b> This will result in a different instance of Model being returned!!!
     *
     * @param model The inbound Model instance, to serialize and reference for expression resolution

   * exercise null handling fail on those subcollections.
   */
  public abstract static class NullsBefore implements Comparator<@Nullable String>, Serializable {
    /*
     * We don't serialize this class in GWT, so we don't care about whether GWT will serialize this
     * field.
     */
    @GwtTransient private final String justAfterNull;

    protected NullsBefore(String justAfterNull) {
      if (justAfterNull == null) {

   * exercise null handling fail on those subcollections.
   */
  public abstract static class NullsBefore implements Comparator<@Nullable String>, Serializable {
    /*
     * We don't serialize this class in GWT, so we don't care about whether GWT will serialize this
     * field.
     */
    @GwtTransient private final String justAfterNull;

    protected NullsBefore(String justAfterNull) {
      if (justAfterNull == null) {

	log.SetPrefix("go_android_exec: ")
	exitCode, err := runMain()
	if err != nil {
		log.Fatal(err)
	}
	os.Exit(exitCode)
}

func runMain() (int, error) {
	// Concurrent use of adb is flaky, so serialize adb commands.
	// See https://github.com/golang/go/issues/23795 or
	// https://issuetracker.google.com/issues/73230216.
	lockPath := filepath.Join(os.TempDir(), "go_android_exec-adb-lock")

```

</div>

Then go to the `/docs` UI, you will see that **FastAPI** is using these **models** to **document** the API, and it will use them to **serialize** and **validate** the data too.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">
</div>

## Update the App with Multiple Models

    }
    return false;
  }

  @Override
  public String toString() {
    return asMapOfRanges().toString();
  }

  /**
   * This class is used to serialize ImmutableRangeMap instances. Serializes the {@link
   * #asMapOfRanges()} form.
   */
  private static class SerializedForm<K extends Comparable<?>, V> implements Serializable {

    private final ImmutableMap<Range<K>, V> mapOfRanges;

    Object unused = memoizedSupplier.get();
    assertThat(memoizedSupplier.toString())
        .isEqualTo("Suppliers.memoize(<supplier that returned 10>)");

    // Should get an exception when we try to serialize.
    RuntimeException ex = assertThrows(RuntimeException.class, () -> reserialize(memoizedSupplier));
    assertThat(ex).hasCauseThat().isInstanceOf(NotSerializableException.class);
  }

  @J2ktIncompatible

    Object unused = memoizedSupplier.get();
    assertThat(memoizedSupplier.toString())
        .isEqualTo("Suppliers.memoize(<supplier that returned 10>)");

    // Should get an exception when we try to serialize.
    RuntimeException ex = assertThrows(RuntimeException.class, () -> reserialize(memoizedSupplier));
    assertThat(ex).hasCauseThat().isInstanceOf(NotSerializableException.class);
  }

  @J2ktIncompatible

}

func (c *ControlzClient) PutScope(scope *ScopeInfo) error {
	var jsonScopeInfo bytes.Buffer
	err := json.NewEncoder(&jsonScopeInfo).Encode(scope)
	if err != nil {
		return fmt.Errorf("cannot serialize scope %+v", *scope)
	}
	req, err := http.NewRequest(http.MethodPut, c.baseURL.String()+"/"+scope.Name, &jsonScopeInfo)
	if err != nil {
		return err
	}
	defer req.Body.Close()