--- on_activate() SNIPPET

if string.sub(staticdata, 1, string.len("return")) ~= "return" then
                return
        end
        local data = minetest.deserialize(staticdata)
        if type(data) ~= "table" then
                return
        end
        self.railtype = data.railtype
        if data.old_dir then
                self.old_dir = data.old_dir
        end

        if data.placets then
        self.placets = data.placets
        end

        if not self.placets then
        self.placets = os.time() + 180
        end

        if os.time() > self.placets then
        self.object:remove()
        return
        end

end

--- get_staticdata() SNIPPET

return minetest.serialize({
                railtype = self.railtype,
                old_dir = self.old_dir,
                placets = self.placets
        })