Schematic-type

schematic = { -- I assume this is comparable to regex but then for nodes
        size = {x=4, y=6, z=4}, --what does size describe?
        data = { -- what is param1 and param2?
            {name="cobble", param1=0, param2=0},
            {name="dirt_with_grass", param1=0, param2=0},
             ...
        }