code: function prepareTooltip() {
                ttScope.title = attrs[prefix + 'Title'];
                if (contentParse) {
                  ttScope.content = contentParse(scope);
                } else {
                  ttScope.content = attrs[ttType];
                }
  
                ttScope.popupClass = attrs[prefix + 'Class'];
                ttScope.placement = angular.isDefined(attrs[prefix + 'Placement']) ? attrs[prefix + 'Placement'] : options.placement;
  
                var delay = parseInt(attrs[prefix + 'PopupDelay'], 10);
                var closeDelay = parseInt(attrs[prefix + 'PopupCloseDelay'], 10);
                ttScope.popupDelay = !isNaN(delay) ? delay : options.popupDelay;
                ttScope.popupCloseDelay = !isNaN(closeDelay) ? closeDelay : options.popupCloseDelay;
              }
docs: Set the inital scope values. Once
  the tooltip is created, the observers
  will be added to keep things in synch.