docstr: Forward at training time. It records the probability
  of generating a ground truth graph following the actions.
docstr_tok: ["Forward","at","training","time",".","It","records","the","probability","of","generating","a","ground","truth","graph","following","the","actions","."]
code: def forward_train(self, actions):
      """Forward at training time. It records the probability
      of generating a ground truth graph following the actions."""
      return NotImplementedError
  
imports: import os
  import dgl
  import torch.nn
  import torch
  from functools import partial
  import torch.nn.functional
  from torch.distributions import Bernoulli
  from torch.distributions import Categorical
  import torch.utils.model_zoo
label_desc: Use image node_id 5 for calling the DGMGSkeleton obj's underlying member method code with example usage: obj.forward_train(actions) and returns: NotImplementedError