question: private static void createNodeVsBlockMapping ( List < NodeBlockRelation > flattenedList , Map < String , List < Distributable > > nodeAndBlockMapping ) { for ( NodeBlockRelation nbr : flattenedList ) { String node = nbr . getNode ( ) ; List < Distributable > list ; if ( null == nodeAndBlockMapping . get ( node ) ) { list = new ArrayList < > ( CarbonCommonConstants . DEFAULT_COLLECTION_SIZE ) ; list . add ( nbr . getBlock ( ) ) ; Collections . sort ( list ) ; nodeAndBlockMapping . put ( node , list ) ; } else { list = nodeAndBlockMapping . get ( node ) ; list . add ( nbr . getBlock ( ) ) ; Collections . sort ( list ) ; } } }
target:  Create the Node and its related blocks Mapping and put in a Map