Method into new function?

I was trying to parse a method in a function, such as

local function x:test()
end
But it does seem to always give an error with ":" or "." , even tho looking around the web it should be possible to do this with LUA...?


Also on the same category (I guess) how can I parse the "region:" to a function I made. For example:

local function findPic(pic)
  if existsClick(pic) then
     toast("found")
  end
end

Region(x,x,x,x):findPic("pic.png")

Is this even possible? I tried using self here and there with no success.

Thank you!