}
@Override
public Map<String, Object> extractEntityTuple(SessionFactory sessionFactory, EntityKey key) {
Map<String, Object> tupleMap = new HashMap<String, Object>();
CouchDBDatastore dataStore = getDataStore( sessionFactory );
EntityDocument entity = dataStore.getEntity( Identifier.createEntityId( key ) );
CouchDBTupleSnapshot snapshot = new CouchDBTupleSnapshot( entity.getProperties() );
Set<String> columnNames = snapshot.getColumnNames();
for ( String columnName : columnNames ) {
tupleMap.put( columnName, snapshot.get( columnName ) );
}