code: def get_lus_from_synset(self, syn_id):
          
  
          root = self.get_synset_xml(syn_id)
          elem_synonyms = root.find( ".//synonyms" )
  
  
          lus = []
          for elem_synonym in elem_synonyms:
              synonym_str = elem_synonym.get( "c_lu_id-previewtext" )        # get "c_lu_id-previewtext" attribute
              # synonym_str ends with ":<num>"
              synonym = synonym_str.split( ':' )[ 0 ].strip()
              lus.append( (synonym, elem_synonym.get( "c_lu_id") ) )
          return lus
docs: Returns a list of (word, lu_id) tuples given a synset ID