code: function showTooltipBind() {
                if (hasEnableExp && !scope.$eval(attrs[prefix + 'Enable'])) {
                  return;
                }
  
                cancelHide();
                prepareTooltip();
  
                if (ttScope.popupDelay) {
                  // Do nothing if the tooltip was already scheduled to pop-up.
                  // This happens if show is triggered multiple times before any hide is triggered.
                  if (!showTimeout) {
                    showTimeout = $timeout(show, ttScope.popupDelay, false);
                  }
                } else {
                  show();
                }
              }
docs: Show the tooltip with delay if specified, otherwise show it immediately