message: Throw error in iterator_seek if iterator has ended
diff: @@ -1367,6 +1367,10 @@ NAPI_METHOD(iterator_seek) {
  NAPI_ARGV(2);
  NAPI_ITERATOR_CONTEXT();
  + if (iterator->ended_) {
  + napi_throw_error(env, NULL, "iterator has ended");
  + }
  +
  iterator->ReleaseTarget();
  iterator->target_ = new leveldb::Slice(ToSlice(env, argv[1]));
  iterator->GetIterator();
  