code: func ProxyPairs(L *lua.State) int {
  	// See Lua >=5.2 source code.
  	if L.GetMetaField(1, "__pairs") {
  		L.PushValue(1)
  		L.Call(1, 3)
  		return 3
  	}
  
  	L.CheckType(1, lua.LUA_TTABLE)
  	L.GetGlobal("next")
  	L.PushValue(1)
  	L.PushNil()
  	return 3
  }
docs: // ProxyPairs implements Lua 5.2 'pairs' functions.
  // It respects the __pairs metamethod.
  //
  // It is only useful for compatibility with Lua 5.1.