code: def score_items(self, X, O, B):
      O = torch.mm(X, O.T) + B.T
      return O
  
imports: from collections import Counter
  import numpy
  import torch
  from torch import nn
  from torch.autograd import Variable
  from torch.optim import Optimizer
  from cornac.utils.common import get_rng
label_desc: Use image node_id 15 for calling the GRU4RecModel obj's underlying member method code with example usage: obj.score_items(X, O, B) and returns: O