code: function hide() {
                cancelShow();
                cancelHide();
  
                if (!ttScope) {
                  return;
                }
  
                // First things first: we don't show it anymore.
                ttScope.$evalAsync(function() {
                  ttScope.isOpen = false;
                  assignIsOpen(false);
                  // And now we remove it from the DOM. However, if we have animation, we
                  // need to wait for it to expire beforehand.
                  // FIXME: this is a placeholder for a port of the transitions library.
                  // The fade transition in TWBS is 150ms.
                  if (ttScope.animation) {
                    if (!transitionTimeout) {
                      transitionTimeout = $timeout(removeTooltip, 150, false);
                    }
                  } else {
                    removeTooltip();
                  }
                });
              }
docs: Hide the tooltip popup element.