docs: public void add(StatementRank rank, Resource subject) {
  		if (this.bestRank == rank) {
  			subjects.add(subject);
  		} else if(bestRank == StatementRank.NORMAL && rank == StatementRank.PREFERRED) {
  			//We found a preferred statement
  			subjects.clear();
  			bestRank = StatementRank.PREFERRED;
  			subjects.add(subject);
  		}
  	}