message: Remove the "copy constructor" from the SerializationRegistry.
  This was added by mistake.
diff: @@ -105,14 +105,6 @@ public final class SerializationRegistry {
  keyParserMap = new HashMap<>(builder.keyParserMap);
  }
  - /**
  - * Creates an new SerializationRegistry with the same registration is the one in {@code other}.
  - */
  - public SerializationRegistry(SerializationRegistry other) {
  - keySerializerMap = new HashMap<>(other.keySerializerMap);
  - keyParserMap = new HashMap<>(other.keyParserMap);
  - }
  -
  private static class SerializerIndex {
  private final Class<?> keyClass;
  private final Class<? extends Serialization> keySerializationClass;
  