## Decision

We do not use Java serialization.
Instead, we use custom serialization where we explicitly describe how data objects should be serialized and deserialized.

For internal purposes, we use binary formats for their brevity.
We use the `Serializer` abstraction to separate the actual implementation of serialization from its uses.

/**
 * Methods factored out so that they can be emulated differently in GWT.
 *
 * @author Chris Povirk
 */
final class Platform {
  /** Serializes and deserializes the specified object (a no-op under GWT). */
  @SuppressWarnings("unchecked")
  static <T> T reserialize(T object) {
    return checkNotNull(object);
  }

  private Platform() {}

 *
 * @author Chris Povirk
 */
@GwtCompatible
@NullMarked
final class Platform {
  /** Serializes and deserializes the specified object. */
  @SuppressWarnings("unchecked")
  static <T> T reserialize(T object) {
    checkNotNull(object);
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    try {
      ObjectOutputStream out = new ObjectOutputStream(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

        assertEquals(exception.getMessage(), deserialized.getMessage());
        assertEquals(exception.getContext().get("key1"), deserialized.getContext().get("key1"));
        assertEquals(exception.getContext().get("key2"), deserialized.getContext().get("key2"));
    }

        assertNotNull(deserialized.getCause());
        assertEquals(original.getCause().getMessage(), deserialized.getCause().getMessage());
        assertEquals(original.getCause().getClass(), deserialized.getCause().getClass());
    }

    /**
     * Test throwing and catching the exception
     */
    public void test_throwAndCatch() {
        try {
            throw new CrawlerSystemException("Test throw");

	if b == nil {
		bb := Bytes(nil)
		return &bb
	}
	bb := NewBytesCap(len(b))
	*bb = append(*bb, b...)
	return bb
}

// Bytes provides a byte slice that can be serialized.
type Bytes []byte

// UnmarshalMsg deserializes b from the provided byte slice and returns the
// remainder of bytes.
func (b *Bytes) UnmarshalMsg(bytes []byte) ([]byte, error) {
	if b == nil {

            oos.close();

            // Deserialize
            ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
            ObjectInputStream ois = new ObjectInputStream(bais);
            CrawlerStatus deserialized = (CrawlerStatus) ois.readObject();
            ois.close();

            // Verify - enum instances are singletons
            assertSame(original, deserialized);

	}

	// Add one more.
	if !replaced {
		keys = append(keys, []byte(key))
		vals = append(vals, value)
		plSize += len(key) + len(value) + msgp.StringPrefixSize + msgp.ArrayHeaderSize
	}

	// Reserialize...
	x.serialize(plSize, keys, vals)
}

// rename will rename a key.
// Returns whether the key was found.
func (x *xlMetaInlineData) rename(oldKey, newKey string) bool {
	in := x.afterVersion()

    return proxyClass.isInstance(arg)
        // Equal proxy instances should mostly be instance of proxyClass
        // Under some edge cases (such as the proxy of JDK types serialized and then deserialized)
        // the proxy type may not be the same.
        // We first check isProxyClass() so that the common case of comparing with non-proxy objects
        // is efficient.