code: def sub_loss_reduction(
      self, sub_losses, embeddings=None, labels=None
  ):
      return torch.sum(sub_losses)
  
imports: import torch
  from .base_reducer import BaseReducer
  from .mean_reducer import MeanReducer
label_desc: Use image node_id 3 for calling the MultipleReducers obj's underlying member method code with example usage: obj.sub_loss_reduction(sub_losses, embeddings, labels) and returns: torch