class_docstr: Reads a file in the conllu Universal Dependencies format. Additionally,
  in order to make it easy to structure a model as predicting arcs, we add a
  dummy 'ROOT_HEAD' token to the start of the sequence.
  
  Parameters
  ----------
  token_indexers : ``Dict[str, TokenIndexer]``, optional (default=``{"tokens": SingleIdTokenIndexer()}``)
      The token indexers to be applied to the words TextField.
class_docstr_tok: ["Reads","a","file","in","the","conllu","Universal","Dependencies","format",".","Additionally",",","in","order","to","make","it","easy","to","structure","a","model","as","predicting","arcs",",","we","add","a","dummy","'ROOT_HEAD","'","token","to","the","start","of","the","sequence",".","Parameters","--","--","--","--","--","token_indexers",":","``","Dict","[","str",",","TokenIndexer","]","``",",","optional","(","default=","``","{","``","tokens","''",":","SingleIdTokenIndexer","(",")","}","``",")","The","token","indexers","to","be","applied","to","the","words","TextField","."]
code: def _read(self, file_path):
      # if `file_path` is a URL, redirect to the cache
      file_path = cached_path(file_path)
  
      with open(file_path, "r") as conllu_file:
          logger.info(
              "Reading UD instances from conllu dataset at: %s",
              file_path,
          )
  
          for annotation in lazy_parse(conllu_file.read()):
              # CoNLLU annotations sometimes add back in words that have been elided
              # in the original sentence; we remove these, as we're just predicting
              # dependencies for the original sentence.
              # We filter by None here as elided words have a non-integer word id,
              # and are replaced with None by the conllu python library.
              annotation = [
                  x for x in annotation if x["id"] is not None
              ]
  
              heads = [x["head"] for x in annotation]
              tags = [x["deprel"] for x in annotation]
              words = [x["form"] for x in annotation]
              pos_tags = [x["upostag"] for x in annotation]
              yield self.text_to_instance(
                  words, pos_tags, list(izip(tags, heads))
              )
  
file_path: magnitude/pymagnitude/third_party/allennlp/data/dataset_readers/universal_dependencies.py
imports: from __future__ import with_statement
  from __future__ import absolute_import
  import logging
  from conllu.parser import parse_line, DEFAULT_FIELDS
  from allennlp.common.file_utils import cached_path
  from allennlp.data.dataset_readers.dataset_reader import DatasetReader
  from allennlp.data.fields import Field, TextField, SequenceLabelField, MetadataField
  from allennlp.data.instance import Instance
  from allennlp.data.token_indexers import SingleIdTokenIndexer, TokenIndexer
  from allennlp.data.tokenizers import Token
  from io import open
label_desc: Use image node_id 2 for calling the UniversalDependenciesDatasetReader obj's underlying member method code with example usage: obj._read(file_path) without return types