class_docstr: Encoder based on a user-supplied vocabulary (file or list).
code: def _safe_id_to_token(self, idx):
      return self._id_to_token.get(idx, "ID_%d" % idx)
  
imports: import re
  import six
label_desc: Use image node_id 7 for calling the TokenTextEncoder obj's underlying member method code with example usage: obj._safe_id_to_token(idx) and returns: self