code: function showTooltipBind() {
                if(hasEnableExp && !scope.$eval(attrs[prefix+'Enable'])) {
                  return;
                }
                if ( scope.tt_popupDelay ) {
                  popupTimeout = $timeout( show, scope.tt_popupDelay, false );
                  popupTimeout.then(function(reposition){reposition();});
                } else {
                  show()();
                }
              }
docs: Show the tooltip with delay if specified, otherwise show it immediately