code: def compute_mat(self, query_emb, ref_emb):
      return torch.matmul(query_emb, ref_emb.t())
  
imports: import torch
  from .base_distance import BaseDistance
label_desc: Use image node_id 2 for calling the DotProductSimilarity obj's underlying member method code with example usage: obj.compute_mat(query_emb, ref_emb) and returns: torch