title: Can Cassandra return an empty set/list instead of null
body: <p>When writing an object that contains an empty Set or List, Cassandra writes this as null.  Therefore, when querying this object it will create an object with a null Set or List.</p>
  
  <p>Is it possible to get Cassandra to create an empty Set/List instead of null, or to not write the null in the first  place?</p>