code: function _initShowAnimation(item, prevItem, size) {
          var spec = item.options.show.animation ? item.options.show.animation.call(undefined, true, size) : {};
          item.startSpec = spec;
          item.endSpec = {
              opacity: 1,
              transform: Transform.identity
          };
          item.mod.halt();
          if (spec.transform) {
              item.mod.setTransform(spec.transform);
          }
          if (spec.opacity !== undefined) {
              item.mod.setOpacity(spec.opacity);
          }
          if (spec.align) {
              item.mod.setAlign(spec.align);
          }
          if (spec.origin) {
              item.mod.setOrigin(spec.origin);
          }
          var startShowAnimation = _startShowAnimation.bind(this, item, spec);
          var waitAndShow = item.wait ? function() {
              item.wait.then(startShowAnimation, startShowAnimation);
          } : startShowAnimation;
          if (prevItem) {
              _initTransferableAnimations.call(this, item, prevItem, waitAndShow);
          }
          else {
              waitAndShow();
          }
      }
docs: Starts the view animation.