@Override
        public void restore(Map<String, Object> state) {
            sessionMap = (ConcurrentHashMap<String, SessionContainer>) state.get("sessionMap");
            sessionContainer = (SessionContainer) state.get("sessionContainer");
            expiredEventChunk = (SessionComplexEventChunk<StreamEvent>) state.get("expiredEventChunk");
        }
Collection used to manage session windows.

@param <E> sub types of ComplexEvent such as StreamEvent and StateEvent.
modules/siddhi-core/src/main/java/io/siddhi/core/query/processor/stream/window/SessionWindowProcessor.java