} else {
			versions = append(versions, fi)
			allVersionIDs = append(allVersionIDs, fi.VersionID)
		}
	}
	buf, err := xl.AppendTo(nil)
	if err != nil {
		t.Fatalf("Failed to serialize xlmeta %v", err)
	}
	fivs, err := getFileInfoVersions(buf, basefi.Volume, basefi.Name, false)
	if err != nil {
		t.Fatalf("getFileInfoVersions failed: %v", err)
	}
	chkNumVersions := func(fis []FileInfo) bool {

        try {
            toolchainsWriter.write(stringWriter, null, toolchains);
        } catch (IOException e) {
            throw new IllegalStateException("Failed to serialize toolchains to memory", e);
        }

        String serializedToolchains = stringWriter.toString();

        RegexBasedInterpolator interpolator = new RegexBasedInterpolator();

        try {

```

</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 { #update-the-app-with-multiple-models }

  public void testEqualsAndHashCode() {
    new EqualsTester()
        .addEqualityGroup(
            MANY_VALUES_PAIRED_STATS,
            DUPLICATE_MANY_VALUES_PAIRED_STATS,
            SerializableTester.reserialize(MANY_VALUES_PAIRED_STATS))
        .addEqualityGroup(
            new PairedStats(MANY_VALUES_STATS_ITERABLE, OTHER_MANY_VALUES_STATS, 1.23),
            new PairedStats(MANY_VALUES_STATS_VARARGS, OTHER_MANY_VALUES_STATS, 1.23))

  public void testEqualsAndHashCode() {
    new EqualsTester()
        .addEqualityGroup(
            MANY_VALUES_PAIRED_STATS,
            DUPLICATE_MANY_VALUES_PAIRED_STATS,
            SerializableTester.reserialize(MANY_VALUES_PAIRED_STATS))
        .addEqualityGroup(
            new PairedStats(MANY_VALUES_STATS_ITERABLE, OTHER_MANY_VALUES_STATS, 1.23),
            new PairedStats(MANY_VALUES_STATS_VARARGS, OTHER_MANY_VALUES_STATS, 1.23))

    /**
     * @throws Exception
     */
    public void testSerialize() throws Exception {
        final String[] a = new String[] { "1", "2" };
        final String[] b = (String[]) SerializeUtil.serialize(a);
        assertEquals("1", b.length, a.length);
        assertEquals("2", "1", b[0]);
        assertEquals("3", "2", b[1]);
    }

    /**
     * @throws Exception
     */

    // Write out all elements in the proper order.
    for (int i = 0; i < length; i++) {
      s.writeDouble(get(i));
    }
  }

  /** Reconstitutes the instance from a stream (that is, deserializes it). */
  private void readObject(ObjectInputStream s) throws IOException, ClassNotFoundException {
    s.defaultReadObject();

    int length = s.readInt();

  }

  public void testSerialization_empty() {
    Collection<String> c = ImmutableSortedMultiset.of();
    assertSame(c, SerializableTester.reserialize(c));
  }

  public void testSerialization_multiple() {
    Collection<String> c = ImmutableSortedMultiset.of("a", "b", "a");
    Collection<String> copy = SerializableTester.reserializeAndAssert(c);

	"syscall"
)

const debug = false

var tmpdir string

var (
	devID    string
	appID    string
	teamID   string
	bundleID string
	deviceID string
)

// lock is a file lock to serialize iOS runs. It is global to avoid the
// garbage collector finalizing it, closing the file and releasing the
// lock prematurely.
var lock *os.File

func main() {
	log.SetFlags(0)
	log.SetPrefix("go_ios_exec: ")

import org.jspecify.annotations.Nullable;

/**
 * Provides static methods for serializing collection classes.
 *
 * <p>This class assists the implementation of collection classes. Do not use this class to
 * serialize collections that are defined elsewhere.
 *
 * @author Jared Levy
 */
@GwtIncompatible
@J2ktIncompatible
final class Serialization {
  private Serialization() {}

  /**