[circonian]

Example: (I combined your New & Initialize functions)

function CustomerList:New()
    local manager = ZO_SortFilterList.New(self, CustomerListContainer)
    manager.masterList = {}
    
    ZO_ScrollList_AddDataType(manager.list, 1, "CustomerUnitRow", 30, function(control, data) manager:SetupUnitRow(control, data) end)
    ZO_ScrollList_EnableHighlight(manager.list, "ZO_ThinListHighlight") 
    manager.sortFunction = function(listEntry1, listEntry2) return ZO_TableOrderingFunction(listEntry1.data, listEntry2.data, manager.currentSortKey, CustomerList.SORT_KEYS, manager.currentSortOrder) end
    manager.sortHeaderGroup:SelectHeaderByKey("name")
    manager:RefreshData()
    
    return manager
end
 
TRADESMAN.CustomerList = CustomerList:New()