session.createQuery( "select g from GuitarPlayer g where g.skill = :skill")
    .setParameter( "skill", Skill.HIGH )
    .list();

java.lang.IllegalArgumentException: can't serialize class org.hibernate.ogm.datastore.mongodb.test.id.GuitarPlayer$Skill
	at org.bson.BasicBSONEncoder._putObjectField(BasicBSONEncoder.java:270)
	at org.bson.BasicBSONEncoder.putObject(BasicBSONEncoder.java:174)
	at org.bson.BasicBSONEncoder.putObject(BasicBSONEncoder.java:120)
	at com.mongodb.DefaultDBEncoder.writeObject(DefaultDBEncoder.java:27)
	at com.mongodb.OutMessage.putObject(OutMessage.java:289)
	at com.mongodb.OutMessage.writeQuery(OutMessage.java:211)
	at com.mongodb.OutMessage.query(OutMessage.java:84)
	at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:307)
	at com.mongodb.DBApiLayer$MyCollection.__find(DBApiLayer.java:295)
	at com.mongodb.DBCursor._check(DBCursor.java:368)
	at com.mongodb.DBCursor._hasNext(DBCursor.java:459)
	at com.mongodb.DBCursor.hasNext(DBCursor.java:484)
	at org.hibernate.ogm.datastore.mongodb.MongoDBDialect$MongoDBResultsCursor.hasNext(MongoDBDialect.java:860)
	at org.hibernate.ogm.query.impl.OgmQueryLoader.listOfEntities(OgmQueryLoader.java:88)
	at org.hibernate.ogm.query.impl.OgmQueryLoader.list(OgmQueryLoader.java:76)
	at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:496)
	at org.hibernate.ogm.query.impl.OgmQueryTranslator.list(OgmQueryTranslator.java:126)
	at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:231)
	at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1264)
	at org.hibernate.internal.QueryImpl.list(QueryImpl.java:103)