Since AbstractHSQuery implements Serializable, ElasticsearchHSQueryImpl should be serializable, but right now it holds reference to objects that aren't serializable through Java's standard serialization (such as JsonObject).

Some test(s) are currently disabled due to this lack of support for serialization. Those should be re-enabled once the problem has been fixed. The test(s) contain this ticket's code in their source code.

Also, QuerySerializationTest is making use of org.hibernate.search.query.engine.spi.HSQuery.luceneQuery(Query) and may require some other changes in order to work properly (make ElasticsearchHSQueryImpl not throw an exception when luceneQuery(null) is called? Make the lucene query a transient attribute in LuceneHSQuery?)