code: def forward(ctx, w_star, dim):
      ctx.save_for_backward(w_star, dim)
      return w_star
  
file_path: pytorch-struct/torch_struct/semirings/sparse_max.py
imports: import torch
  from .semirings import _BaseLog
label_desc: Use image node_id 1 for calling the _SparseMaxGrad obj's underlying member method code with example usage: obj.forward(ctx, w_star, dim) and returns: w_star