code: def process_rollout(self, batch_info, rollout: Rollout):
          
          assert isinstance(rollout, Trajectories), "A2C requires trajectory rollouts"
  
          advantages = discount_bootstrap_gae(
              rewards_buffer=rollout.transition_tensors['rewards'],
              dones_buffer=rollout.transition_tensors['dones'],
              values_buffer=rollout.transition_tensors['values'],
              final_values=rollout.rollout_tensors['final_values'],
              discount_factor=self.discount_factor,
              gae_lambda=self.gae_lambda,
              number_of_steps=rollout.num_steps
          )
  
          returns = advantages + rollout.transition_tensors['values']
  
          rollout.transition_tensors['advantages'] = advantages
          rollout.transition_tensors['returns'] = returns
  
          return rollout
docs: Process rollout for ALGO before any chunking/shuffling