code: def __init__(self, n_vocab, n_pos):
      super(CRF, self).__init__()
      with self.init_scope():
          self.feature = L.EmbedID(n_vocab, n_pos)
          self.crf = L.CRF1d(n_pos)
  
file_path: chainer/examples/pos/postagging.py
imports: import argparse
  import collections
  import warnings
  import nltk
  import numpy
  import six
  import chainer
  from chainer import datasets
  import chainer.links
  from chainer import reporter
  from chainer import training
  from chainer.training import extensions
label_desc: Use image node_id 1 to create a new CRF object from inherited base classes: chainer with example: obj = CRF(n_vocab, n_pos)