text:   var PairwiseObservable = (function (__super__) {
      inherits(PairwiseObservable, __super__);
      function PairwiseObservable(source) {
        this.source = source;
        __super__.call(this);
      }
  
      PairwiseObservable.prototype.subscribeCore = function (o) {
        return this.source.subscribe(new PairwiseObserver(o));
      };
  
      return PairwiseObservable;
    }(ObservableBase));
  
    var PairwiseObserver = (function(__super__) {
      inherits(PairwiseObserver, __super__);
      function PairwiseObserver(o) {
        this._o = o;
        this._p = null;
        this._hp = false;
      }
  
      PairwiseObserver.prototype.next = function (x) {
        if (this._hp) {
          this._o.onNext([this._p, x]);
        } else {
          this._hp = true;
        }
        this._p = x;
      };
      PairwiseObserver.prototype.error = function (err) { this._o.onError(err); };
      PairwiseObserver.prototype.completed = function () { this._o.onCompleted(); };
  
      return PairwiseObserver;
    }(AbstractObserver));
  
    /**
     * Returns a new observable that triggers on the second and subsequent triggerings of the input observable.
     * The Nth triggering of the input observable passes the arguments from the N-1th and Nth triggering as a pair.
     * The argument passed to the N-1th triggering is held in hidden internal state until the Nth triggering occurs.
     * @returns {Observable} An observable that triggers on successive pairs of observations from the input observable as an array.
     */
    observableProto.pairwise = function () {
      return new PairwiseObservable(this);
    };
  