code: public void setComments(String tag, List<String> comments) {
          String nt = normaliseTag(tag);
          if(this.comments.containsKey(nt)) {
              this.comments.remove(nt);
          }
          this.comments.put(nt, comments);
      }
docs: Removes any existing comments for a given tag,
  and replaces them with the supplied list