code: function (e) {
          if (e && e.prevValue === e.newValue) {
              return;
          }
  
          var par   = this.current ? this.current.parentNode : null,
              after = this.link;
  
          if (par) {
              switch (this.paginator.getTotalPages()) {
                  case Paginator.VALUE_UNLIMITED :
                          after = this.na; break;
                  case this.paginator.getCurrentPage() :
                          after = this.span; break;
              }
  
              if (this.current !== after) {
                  par.replaceChild(after,this.current);
                  this.current = after;
              }
          }
      }
docs: Swap the link, span, and na nodes if appropriate.
  @method update
  @param e {CustomEvent} The calling change event (ignored)