class_docstr: Process unit to remove stop words.
  
  Example:
      >>> unit = StopRemoval()
      >>> unit.transform(['a', 'the', 'test'])
      ['test']
      >>> type(unit.stopwords)
      <class 'list'>
docstr: Remove stopwords from list of tokenized tokens.
  
  :param input_: list of tokenized tokens.
  :param lang: language code for stopwords.
  
  :return tokens: list of tokenized tokens without stopwords.
docstr_tok: ["Remove","stopwords","from","list","of","tokenized","tokens",".",":","param","input_",":","list","of","tokenized","tokens",".",":","param","lang",":","language","code","for","stopwords",".",":","return","tokens",":","list","of","tokenized","tokens","without","stopwords","."]
code: def transform(self, input_: list) -> list:
      """
      Remove stopwords from list of tokenized tokens.
  
      :param input_: list of tokenized tokens.
      :param lang: language code for stopwords.
  
      :return tokens: list of tokenized tokens without stopwords.
      """
      return [token for token in input_ if token not in self._stop]
  
imports: import nltk
  from .unit import Unit
label_desc: Use image node_id 2 for calling the StopRemoval obj's underlying member method code with example usage: obj.transform(input_) and returns: unknown