fbb_.AddOffset(Buffer::VT_DATA, data);
  }
  void add_offset(uint64_t offset) {
    fbb_.AddElement<uint64_t>(Buffer::VT_OFFSET, offset, 0);
  }
  void add_size(uint64_t size) {
    fbb_.AddElement<uint64_t>(Buffer::VT_SIZE, size, 0);
  }
  explicit BufferBuilder(::flatbuffers::FlatBufferBuilder &_fbb)
        : fbb_(_fbb) {
    start_ = fbb_.StartTable();
  }