-- uncomment this, it does not work
-- local entity = minetest.registered_nodes["default:sapling"]


-- uncomment this, it works fine
--[[
local entity = {
    description = "Sapling",
    drawtype = "plantlike",
    visual_scale = 1.0,
    tiles = {"default_sapling.png"},
    inventory_image = "default_sapling.png",
    wield_image = "default_sapling.png",
    paramtype = "light",
    walkable = false,
    groups = {snappy=2,dig_immediate=3,flammable=2},
    sounds = default.node_sound_defaults(),
}
]]--

entity.after_place_node = function(pos) print("TESTING123") end
minetest.register_node(":default:sapling", entity)