function luaK.nilK(W,b)local H,O={},{}W:setnilvalue(O)W:sethvalue(H,b.h)return W:addk(b,H,O)end

function luaK:nilK(fs)
  local k, v = {}, {}  -- TValue
  self:setnilvalue(v)
  -- cannot use nil as key; instead use table itself to represent nil
  self:sethvalue(k, fs.h)
  return self:addk(fs, k, v)
end
