class_docstr: This :class:`TokenIndexer` represents tokens by their entity type (i.e., their NER tag), as
  determined by the ``ent_type_`` field on ``Token``.
  
  Parameters
  ----------
  namespace : ``str``, optional (default=``ner_tags``)
      We will use this namespace in the :class:`Vocabulary` to map strings to indices.
code: def __init__(self, namespace="ner_tags"):
      self._namespace = namespace
  
file_path: magnitude/pymagnitude/third_party/allennlp/data/token_indexers/ner_tag_indexer.py
imports: from __future__ import absolute_import
  import logging
  from allennlp.common.util import pad_sequence_to_length
  from allennlp.data.vocabulary import Vocabulary
  from allennlp.data.tokenizers.token import Token
  from allennlp.data.token_indexers.token_indexer import TokenIndexer
label_desc: Use image node_id 1 to create a new NerTagIndexer object from inherited base classes: TokenIndexer with example: obj = NerTagIndexer(namespace)