docs: public SequenceReferenceSeqComponent addReferenceSeq() { //3
        SequenceReferenceSeqComponent t = new SequenceReferenceSeqComponent();
        if (this.referenceSeq == null)
          this.referenceSeq = new ArrayList<SequenceReferenceSeqComponent>();
        this.referenceSeq.add(t);
        return t;
      }