func getEquipmentHistory(for group: [String]) -> [Equipment] {
        if self.historyList.count > 0 {
            let historyList = self.historyList.filter({group.contains($0.equipment.group1)})
            let sorted = historyList.sorted(by: { (aData, bData) -> Bool in
                aData.dateAdded > bData.dateAdded
            })
            var list : [Equipment] = []
            for item in sorted {
                list.append(item.equipment)
            }

            let cut_down : ArraySlice<Equipment> = list.prefix(HISTORY_LIMIT)
            self.currentHistoryList = Array(cut_down)
            return self.currentHistoryList
        }
        return []
    }