code: func MakeChan(L *lua.State) int {
  	n := L.OptInteger(1, 0)
  	ch := make(chan interface{}, n)
  	makeValueProxy(L, reflect.ValueOf(ch), cChannelMeta)
  	return 1
  }
docs: // MakeChan creates a 'chan interface{}' proxy and pushes it on the stack.
  //
  // Optional argument: size (number)
  //
  // Returns: proxy (chan interface{})