Where is the sd.reset in CudaIPCSentDataLimbo::collect

I can not find the function rd.reset(). Where is the following code?

bool CudaIPCSentDataLimbo::collect() {
  bool freed_memory = false;
  std::vector<std::unique_ptr<CudaIPCSentData>> reset_blocks;
  { // Begin critical section to modify shared blocks
    std::lock_guard<std::mutex> lock(limbo_mutex_);
    std::vector<std::unique_ptr<CudaIPCSentData>> kept_blocks;
    for (auto& sd : shared_blocks_) {
      if (sd->counter_value() > 0) {
        kept_blocks.push_back(std::move(sd));
      } else {
        freed_memory = true;
        reset_blocks.push_back(std::move(sd));
      }
    }
    shared_blocks_ = std::move(kept_blocks);
  }
  // Need to reset blocks out of the critical section here, otherwise it deadlocks.
  for (auto& sd : reset_blocks) {
    sd.reset();
  }
  return freed_memory;
}