async function saveAll(items) {
        const now = new Date()
        return await _getTableContext()
            .insert(items.map(item => ({
                id: item.id,
                name: item.name,
                balance: item.balance,
                updated_at: now,
            })))
            .onConflict('id')
            .merge()
            .returning('id')
    }
@param {UserItem[]} items
@returns {Promise<string[]>} list of items IDs