* its class information. The serialized data is written to a byte array
     * output stream.
     * </p>
     *
     * @param obj the object to serialize
     * @return the serialized object as a byte array
     * @throws IORuntimeException if an I/O error occurs during serialization
     */
    protected byte[] serializeWithKryo(final Object obj) {

		if err != nil {
			return keys, err
		}
	}
	return keys, nil
}

// serialize will serialize the provided keys and values.
// The function will panic if keys/value slices aren't of equal length.
// Payload size can give an indication of expected payload size.
// If plSize is <= 0 it will be calculated.
func (x *xlMetaInlineData) serialize(plSize int, keys [][]byte, vals [][]byte) {
	if len(keys) != len(vals) {

        assertTrue(s.contains("hello"));
    }

    @Test
    @DisplayName("Should serialize and deserialize preserving message and cause")
    void testJavaSerialization() throws Exception {
        // Given
        SpnegoException original = new SpnegoException("serialize me", new IllegalArgumentException("iaex"));

        // When
        byte[] bytes;

	// Set WantParts to indicate 3 parts
	finalChecksum.WantParts = 3

	// Test AppendTo serialization
	var serialized []byte
	serialized = finalChecksum.AppendTo(serialized, checksumCombined)

	// Use ChecksumFromBytes to deserialize the final checksum
	chksmOut := ChecksumFromBytes(serialized)
	if chksmOut == nil {
		t.Fatal("ChecksumFromBytes returned nil")
	}

	// Assert they are exactly equal

        return ObjectInputFilter.Status.REJECTED;
    };

    /**
     * Tests if the object can be serialized.
     *
     * @param obj the object to be serialized (must not be {@literal null})
     * @return the deserialized object
     */
    public static Object serialize(final Object obj) {
        assertArgumentNotNull("obj", obj);

        final byte[] binary = fromObjectToBinary(obj);

# Currently, there is no way to pass multiple cookies with the same name.
# The only way to pass multiple values for cookie params is to serialize them using

# Currently, there is no way to pass multiple cookies with the same name.
# The only way to pass multiple values for cookie params is to serialize them using

		} 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 {

    /**
     * @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
     */

```

</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 }