code: function getTriggers ( trigger ) {
          var show = trigger || options.trigger || defaultTriggerShow;
          var hide = triggerMap[show] || show;
          return {
            show: show,
            hide: hide
          };
        }
docs: Returns an object of show and hide triggers.
  
  If a trigger is supplied,
  it is used to show the tooltip; otherwise, it will use the `trigger`
  option passed to the `$tooltipProvider.options` method; else it will
  default to the trigger supplied to this directive factory.
  
  The hide trigger is based on the show trigger. If the `trigger` option
  was passed to the `$tooltipProvider.options` method, it will use the
  mapped trigger from `triggerMap` or the passed trigger if the map is
  undefined; otherwise, it uses the `triggerMap` value of the show
  trigger; else it will just use the show trigger.