local Class = {}
Class.__index = Class
function Class.new(v) return setmetatable({v=v}, Class) end
function Class:A() return "A"..self.v end
function Class:B(x) return "B"..self.v..tostring(x) end
local originalNew = Class.new
Class.new = function(...)
    local w = originalNew(...)
    w.captured = true
    return w
end
local originals = {}
for _, name in ipairs({"A", "B"}) do
    local original = Class[name]
    if type(original) == "function" then
        originals[name] = original
        Class[name] = function(self, ...)
            return original(self, ...)
        end
    end
end
local w = Class.new(7)
print(w:A(), w:B(9))
local c = getmetatable(w)
for n, f in pairs(c) do if type(f)=="function" then print(n, f(w, 9)) end end