This breaks backward compatibility of the stream format, so you need to only read this boolean if the node that is sending this request to you has a recent enough version of Elasticsearch. It would look something like:
```java
if (in.getVersion().onOrAfter(Version.V_1_2_0)) {
  include = in.readBoolean();
} else {
  include = false; // hard-coded behavior until Elasticsearch 1.2
}
```