Neo4j Cypher query

t2g-cypher-query.java

		query.append("START activity = node:__types__(className={activityClass}) ")
//			.append("MATCH (activity)-[*1..2]->(source), ")
//			.append("(source)<-[:HAS_SOURCE]-(lastActivities) ")
			.append("MATCH (activity)-[*1..2]->(source)<-[:HAS_SOURCE]-(lastActivities) ")
			.append("WHERE source.__type__ in {sourceTypes} ")
			.append("RETURN source as source, COLLECT(lastActivities) as activities ")
//			.append("ORDER BY activity.when DESC LIMIT 20"); why can't I use activity anymore? because of second match
			.append("LIMIT 20");

You cannot use activity anymore because you aggregated on source, so the activities are only in the list. What you want is to sort and limit the collection, which is planned in cypher but there is no implementation date yet.