code: private static Map<String,List<ViewRiksdagenVoteDataBallotPartySummary>> createIssueConcernMap(final List<ViewRiksdagenVoteDataBallotPartySummary> partyBallotList) {
  		final Map<String,List<ViewRiksdagenVoteDataBallotPartySummary>> concernIssuePartyBallotSummaryMap = new HashMap<>();
  		for (final ViewRiksdagenVoteDataBallotPartySummary partySummary: partyBallotList) {
  
  			if (partySummary.getEmbeddedId().getIssue() !=null || partySummary.getEmbeddedId().getConcern() != null ) {
  				final String key = partySummary.getEmbeddedId().getIssue() + partySummary.getEmbeddedId().getConcern();
  				final List<ViewRiksdagenVoteDataBallotPartySummary> partySummarList = concernIssuePartyBallotSummaryMap.computeIfAbsent(key, k -> new ArrayList<>());				
  				partySummarList.add(partySummary);
  			}
  		}
  
  		return concernIssuePartyBallotSummaryMap;
  	}
docs: Creates the issue concern map.
  
  @param partyBallotList
  the party ballot list
  @return the map