class_docstr: Transformation that inserts synonyms of words that are already in the
  sequence.
code: def _get_synonyms(self, word):
      synonyms = set()
      for syn in wordnet.synsets(word):
          for lemma in syn.lemmas():
              if lemma.name() != word and check_if_one_word(
                  lemma.name()
              ):
                  synonyms.add(lemma.name())
      return list(synonyms)
  
file_path: TextAttack/textattack/transformations/word_insertions/word_insertion_random_synonym.py
imports: import random
  from nltk.corpus import wordnet
  from .word_insertion import WordInsertion
label_desc: Use image node_id 1 for calling the WordInsertionRandomSynonym obj's underlying member method code with example usage: obj._get_synonyms(word) and returns: list