code: public void asFlatFile(@NonNull File file) throws IOException {
          val fb = asFlatBuffers();
          val offset = fb.position();
  
          val array = fb.array();
  
          try (val fos = new FileOutputStream(file); val bos = new BufferedOutputStream(fos); val dos = new DataOutputStream(bos)) {
              dos.write(array, offset, array.length - offset);
          }
      }
docs: This method converts SameDiff instance to
  FlatBuffers and saves it to file which
  can be restored later
  
  @param file File to save the FlatBuffers serialized graph (including arrays) to