[Creating new java classes in lua]

I can create a class like this

local noise = InventoryItemFactory.CreateItem("Peace.SoundBeacon");
local noiseTrap = IsoTrap.new(noise, cell, square);
noiseTrap:addToWorld();

but I cant create some classes, i get an is nil error

local radioLinePre = RadioLine.new("Test Message", 1, 1, 1);

Is it just that some of the classes arent accessible in lua, or am i missing a namespace or something?

I dont have much experience with lua.