code: function Pager(ref, initialCount) {
  
    if (arguments.length < 1) {
      throw new Error('Not enough arguments to Pager');
    }
  
    this._mainRef = ref.ref();
    this._resetCurrentOperation();
  
    this.hasNext = true;
    this.hasPrevious = false;
  
    var promise;
    if (initialCount) {
      promise = this.next(initialCount);
    } else {
      promise = Fireproof.Promise.resolve([]);
    }
     
    this.then = promise.then.bind(promise);
  
  }
docs: A helper object for paging over Firebase objects.
  @constructor Fireproof.Pager
  @static
  @param {Fireproof} ref a Firebase ref whose children you wish to page over.
  @param {Number} [initialCount] The number of objects in the first page.
  @property {Boolean} hasPrevious True if there are more objects before the current page.
  @property {Boolean} hasNext True if there are more objects after the current page.