void* Init(TfLiteContext* context, const char* buffer, size_t length) {
  // This is a builtin op, so we don't use the contents in 'buffer', if any.
  // Instead, we allocate a new object to carry information from Prepare() to
  // Eval().
  auto* op_data = new OpData();
  context->AddTensors(context, /*tensors_to_add=*/6,
                      &op_data->scratch_tensor_index);
  return op_data;
}