def dispatch_item_id!(iid)
      type = iid.keys.first
      item = iid[type]
      case type
      when :item_id
        item_id!(item)
      when :occurrence_item_id
        occurrence_item_id!(item)
      when :recurring_master_item_id
        recurring_master_item_id!(item)
      else
        raise EwsBadArgumentError, "Bad ItemId type. #{type}"
      end
    end
def dispatch_item_id!(iid)
      type = iid.keys.first
      item = iid[type]
      case type
      when :item_id
        item_id!(item)
      when :occurrence_item_id
        occurrence_item_id!(item)
      when :recurring_master_item_id
        recurring_master_item_id!(item)
      else
        raise EwsBadArgumentError, "Bad ItemId type. #{type}"
      end
    end
A helper method to dispatch to an ItemId, OccurrenceItemId, or a RecurringMasterItemId
 @param [Hash] iid The item id of some type