@Nullable
  public Long serialVersionUID() {
    Protoclass p = constitution.protoclass();
    if (p.serialVersion().isPresent()) {
      return p.serialVersion().get();
    }
    return serial.isEnabled()
        ? findSerialVersionUID()
        : null;
  }
Should be called when it is known that there type adapters generation provided.
@return the type adapters annotation
value-processor/src/org/immutables/value/processor/meta/ValueType.java