class_docstr: A container for the nodes and labelled edges of a dependency structure.
docstr: The dependency graph in CoNLL format.
  
  :param style: the style to use for the format (3, 4, 10 columns)
  :type style: int
  :rtype: str
docstr_tok: ["The","dependency","graph","in","CoNLL","format",".",":","param","style",":","the","style","to","use","for","the","format","(","3",",","4",",","10","columns",")",":","type","style",":","int",":","rtype",":","str"]
code: def to_conll(self, style):
      """
      The dependency graph in CoNLL format.
  
      :param style: the style to use for the format (3, 4, 10 columns)
      :type style: int
      :rtype: str
      """
  
      if style == 3:
          template = "{word}\t{tag}\t{head}\n"
      elif style == 4:
          template = "{word}\t{tag}\t{head}\t{rel}\n"
      elif style == 10:
          template = "{i}\t{word}\t{lemma}\t{ctag}\t{tag}\t{feats}\t{head}\t{rel}\t_\t_\n"
      else:
          raise ValueError(
              "Number of tab-delimited fields ({}) not supported by "
              "CoNLL(10) or Malt-Tab(4) format".format(style)
          )
  
      return "".join(
          template.format(i=i, **node)
          for i, node in sorted(self.nodes.items())
          if node["tag"] != "TOP"
      )
  
imports: import subprocess
  import warnings
  from collections import defaultdict
  from itertools import chain
  from pprint import pformat
  from nltk.internals import find_binary
  from nltk.tree import Tree
label_desc: Use image node_id 25 for calling the DependencyGraph obj's underlying member method code with example usage: obj.to_conll(style) and returns: str