question: protected void addNewEvent ( Object eventKey , T event ) { if ( unwrittenEvents == null ) { unwrittenEvents = Maps . newHashMap ( ) ; } List < T > listEvents = unwrittenEvents . get ( eventKey ) ; if ( listEvents == null ) { unwrittenEvents . put ( eventKey , Lists . newArrayList ( event ) ) ; } else { listEvents . add ( event ) ; } }
target:  Add the given event into the unwritternEvents map