code: def enumerate(semiring, arc_scores, non_proj=False, multi_root=True):
      parses = []
      q = []
      arc_scores = torch_struct.convert(arc_scores)
      batch, N, _ = arc_scores.shape
  
      # arc_scores = arc_scores.sum(-1)
      for mid in itertools.product(range(N + 1), repeat=N - 1):
          parse = [-1] + list(mid)
          if not _is_spanning(parse):
              continue
          if not non_proj and not _is_projective(parse):
              continue
  
          if not multi_root and _is_multi_root(parse):
              continue
  
          q.append(parse)
          parses.append(
              semiring.times(
                  *[arc_scores[:, parse[i], i] for i in range(1, N, 1)]
              )
          )
      return semiring.sum(torch.stack(parses, dim=-1)), None
  
imports: import torch_struct
  import torch
  from torch_struct import LogSemiring
  import itertools
  from hypothesis.strategies import integers, composite, floats
  from hypothesis.extra.numpy import arrays
  import numpy
label_desc: Use image node_id 2 for calling the DepTreeTest obj's underlying member method code with example usage: obj.enumerate(semiring, arc_scores, non_proj, multi_root) and returns: semiring,  None