class_docstr: Process unit to remove stop words.
  
  Example:
      >>> unit = StopRemoval()
      >>> unit.transform(['a', 'the', 'test'])
      ['test']
      >>> type(unit.stopwords)
      <class 'list'>
docstr: Initialization.
docstr_tok: ["Initialization","."]
code: def __init__(self, lang: str = "english"):
      """Initialization."""
      self._lang = lang
      self._stop = nltk.corpus.stopwords.words(self._lang)
  
imports: import nltk
  from .unit import Unit
label_desc: Use image node_id 1 to create a new StopRemoval object from inherited base classes: Unit with example: obj = StopRemoval(lang)