code: def spanning_tree_count(graph: nx.Graph) -> int:
      
      laplacian = nx.laplacian_matrix(graph).toarray()
      comatrix = laplacian[:-1, :-1]
      det = np.linalg.det(comatrix)
      count = int(round(det))
      return count
docs: Return the number of unique spanning trees of a graph, using
      Kirchhoff's matrix tree theorem.