class_docstr: Standalone version of 'model' function found in UnigramTagger; by
  defining as its own class, it is clearer that this lemmatizer is
  based on dictionary lookup and does not use training data.
class_docstr_tok: ["Standalone","version","of","'model","'","function","found","in","UnigramTagger",";","by","defining","as","its","own","class",",","it","is","clearer","that","this","lemmatizer","is","based","on","dictionary","lookup","and","does","not","use","training","data","."]
docstr: Looks up token in ``lemmas`` dict and returns the corresponding
  value as lemma.
  :rtype: str
  :type tokens: list
  :param tokens: List of tokens to be lemmatized
  :type index: int
  :param index: Int with current token
  :type history: list
  :param history: List with tokens that have already been lemmatized; NOT USED
docstr_tok: ["Looks","up","token","in","``","lemmas","``","dict","and","returns","the","corresponding","value","as","lemma",".",":","rtype",":","str",":","type","tokens",":","list",":","param","tokens",":","List","of","tokens","to","be","lemmatized",":","type","index",":","int",":","param","index",":","Int","with","current","token",":","type","history",":","list",":","param","history",":","List","with","tokens","that","have","already","been","lemmatized",";","NOT","USED"]
code: def choose_tag(
      self, tokens: List[str], index: int, history: List[str]
  ):
      """
      Looks up token in ``lemmas`` dict and returns the corresponding
      value as lemma.
      :rtype: str
      :type tokens: list
      :param tokens: List of tokens to be lemmatized
      :type index: int
      :param index: Int with current token
      :type history: list
      :param history: List with tokens that have already been lemmatized; NOT USED
      """
      keys = self.lemmas.keys()
      if tokens[index] in keys:
          return self.lemmas[tokens[index]]
  
imports: import re
  import reprlib
  from typing import Dict, List, Optional, Tuple
  from nltk.tag.sequential import RegexpTagger, SequentialBackoffTagger, TaggerI, UnigramTagger
label_desc: Use image node_id 2 for calling the DictLemmatizer obj's underlying member method code with example usage: obj.choose_tag(tokens, index, history) and returns: self