code: def string_to_configs(s):
      
  
      s = lexer(s)
      value = None
      if s.pos == len(s):
          value = set()
      elif s.cur == '{':
          value = parse_set(s)
      elif s.cur == '(':
          value = {parse_tuple(s)}
      else:
          value = {tuple(parse_multiple(s, parse_store))}
      parse_end(s)
  
      return value
docs: s is a string in one of the following formats:
         - x,y
         - (x,y)
         - {x,y}
         - {(w,x),(y,z)}
         In any case, returns a set of tuples of stores.