Class = {}
Class.__index = Class
  
function Class.new(x,y)
    local cls = {}
    setmetatable(cls, Class)
    cls.x = x
    cls.y = y
    return cls
end
function Class:test()
    -- 等价于
    -- function Class.test(self)
    print(self.x,self.y)
end

object = Class.new(10,20)
 
object:test() -- 等价于
object.test(object)