code: def enumerate_spanning_trees(V):
      """
      Compute the set of spanning trees on V vertices.
      """
      if V >= len(_TREE_GENERATORS):
          raise NotImplementedError(
              "enumerate_spanning_trees() is implemented only for trees with up to {} vertices".format(
                  len(_TREE_GENERATORS) - 1
              )
          )
      all_trees = _close_under_permutations(V, _TREE_GENERATORS[V])
      assert len(all_trees) == NUM_SPANNING_TREES[V]
      return all_trees
  
imports: import itertools
  import math
  import torch
  from torch.distributions import constraints
  from torch.distributions.utils import lazy_property
  from pyro.distributions.torch_distribution import TorchDistribution
label_desc: Use image node_id 16 for calling a global function with example usage: enumerate_spanning_trees(V) and returns: all_trees