问graph-tool - 'NestedBlockState‘对象没有属性'get_nonempty_B’

EN

import graph_tool.all as gt
import cPickle as pickle

g = gt.load_graph('graph_no_multi_reac_type.gt')
gt.remove_parallel_edges(g)

state = gt.minimize_nested_blockmodel_dl(g, deg_corr=True)

state = state.copy(sampling=True)
with open('state_mcmc.pkl','wb') as state_pkl:
    pickle.dump(state,state_pkl,-1)

print 'equilibrating Markov chain'
gt.mcmc_equilibrate(state, wait=1000, mcmc_args=dict(niter=10))

h = np.zeros(g.num_vertices() + 1)

def collect_num_groups(s):
    B = s.get_nonempty_B()
    h[B] += 1

print 'colleting marginals'
gt.mcmc_equilibrate(state, force_niter=10000, mcmc_args=dict(niter=10),
                callback=collect_num_groups)
with open('state_ncnc.pkl','wb') as state_pkl:
    pickle.dump(state,state_pkl,-1)

with open('hist.pkl','wb') as h_pkl:
    pickle.dump(h,h_pkl,-1)

Traceback (most recent call last):
  File "num_groups_marg_prob.py", line 42, in <module>
        gt.mcmc_equilibrate(state, force_niter=10000, mcmc_args=dict(niter=10),
  File "/usr/lib/python2.7/dist-packages/graph_tool/inference/mcmc.py", line 172, in mcmc_equilibrate
        extra = callback(state)
  File "num_groups_marg_prob.py", line 35, in collect_num_groups
        def collect_num_groups(s):
AttributeError: 'NestedBlockState' object has no attribute 'get_nonempty_B'