function Signal.Once(E,b)local p p=E:Connect(function(...)if p._connected then p:Disconnect()end b(...)end)return p end
-- Implement Signal:Once() in terms of a connection which disconnects
-- itself before running the handler.
function Signal:Once(fn)
	local cn
	cn = self:Connect(function(...)
		if cn._connected then
			cn:Disconnect()
		end
		fn(...)
	end)
	return cn
end
