Custom Gamemode issue

Im working on a custom gamemode but i have run into a bit of a bump. See i just started learning and i would like help fixing this error in the console im getting


[ERROR] gamemodes/base/gamemode/shared.lua:10: attempt to index field 'BaseClass' (a nil value)
  1. unknown - gamemodes/base/gamemode/shared.lua:10


this is my Shared.lua


GM.Name 	= "Skeleton Gamemode"
GM.Author 	= "N/A"
GM.Email 	= "N/A"
GM.Website 	= "N/A"

DeriveGamemode("sandbox")

function GM:Initialize()
	self.baseclass.Initialize( self )
end

//Teams
team.SetUp( 1, "Dealers", Color(255, 255, 0, 255))
team.SetUp( 2, "Spenders", Color(0, 255, 255, 255))
team.SetUp( 3, "Bankers", Color(255, 0, 255, 255))
//Models
util.PrecacheModel("model/player/arctic.mdl")
util.PrecacheModel("model/player/leet.mdl")
util.PrecacheModel("model/player/alyx.mdl")


Any ideas. Again i am sorry if this is just a simple error as i’m new

Your error says BaseClass, but your initialize says baseclass.

OH WOW i feel like an absolute tick now for not spotting that thank you so much. I thought some of functions need to be lower case guess not