NetGroup

function wrap(side, filter)
    local obj = {}
    local members = {}
--  local filter = filter

    function obj:__index(index)
        return function(...)
            assert(filter, 'No peripheral filter set! Use group.filter')
            local returns = {}

            for i, periph in pairs(members) do
                if peripheral.getType(i) == filter then
                    local value = periph[index]
                    assert(value, filter..'.'..index..' does not exist')

                    local args = {...}
                    if type(args[1]) == 'function' then
                        local res = {args[1](periph, i)}
                        args = #res > 0 and res or nil
                    end

                    if args then
                        if type(value) == 'function' then
                            local res = {value(unpack(args))}
                            if res then
                                returns[i] = res
                            end
                        else
                            returns[i] = value
                        end
                    end
                end
            end

            return setmetatable(returns, returns)
        end
    end

    function obj.filter(new_filter)
        filter = new_filter or filter
        return filter
    end

    local modem = peripheral.wrap(side)
    local periphs = modem.getNamesRemote()
    for i=1, #periphs do
        local wrapped = peripheral.wrap(periphs[i])
    --  members[i] = wrapped
        members[periphs[i]] = wrapped
    end

    return setmetatable(obj, obj)
end