code: def _get_key_from_raw_synset(raw_synset):
      
      pos = raw_synset.pos
      literal = raw_synset.variants[0].literal
      sense = "%02d"%raw_synset.variants[0].sense
      return '.'.join([literal,pos,sense])
docs: Derives synset key in the form of `lemma.pos.sense_no` from the provided eurown.py Synset class,
  
      Notes
      -----
      Internal function. Do not call directly.
  
  
      Parameters
      ----------
      raw_synset : eurown.Synset
        Synset representation from which lemma, part-of-speech and sense is derived.
  
      Returns
      -------
      string
        Key of the synset in the form of `lemma.pos.sense_no`.