code: private List<EntityIdValue> getItemIdValueList(StatementGroup statementGroup) {
  		List<EntityIdValue> result = new ArrayList<>(statementGroup.size());
  
  		for (Statement s : statementGroup) {
  			Value v = s.getValue();
  			if (v instanceof EntityIdValue) {
  				result.add((EntityIdValue) v);
  			}
  		}
  
  		return result;
  	}
docs: Helper method that extracts the list of all {@link ItemIdValue} objects
  that are used as values in the given statement group.
  
  @param statementGroup
  the {@link StatementGroup} to extract the data from
  @return the list of values