public Object execute(ComplexEvent event) {
        List values = new LinkedList();
        StreamEvent aEvent = ((StateEvent) event).getStreamEvent(position);
        while (aEvent != null) {
            values.add(aEvent.getAttribute(position));
            aEvent = aEvent.getNext();
        }
        return values;
    }
Executor class for Siddhi event attribute that produces multiple values.
This executor is used to extract multiple attribute values as a list from
{@link ComplexEvent}.
modules/siddhi-core/src/main/java/io/siddhi/core/executor/MultiValueVariableFunctionExecutor.java