code: def read_file(filename):
      
      sanitized_filename = sanitize(filename)
  
      f = open(sanitized_filename)
  
      specs = None
  
      try:
          specs = _parse_tsplib(f)
      except ParseException:
          raise
      finally: # 'finally' is executed even when we re-raise exceptions
          f.close()
  
      if specs['TYPE'] != 'CVRP':
          raise Exception('Not a CVRP TSPLIB problem. Found: {}'.format(specs['TYPE']))
      
      #additional params for graph/network (temporary)
      specs['VOLTAGE'] = 20000
      specs['CABLETYPE'] = 1
  
      #return (Graph(specs), specs)
      return Graph(specs)
docs: Reads a TSPLIB file and returns the problem data.
      
      Args
      ----
      filename: str
      
      Returns
      -------
      type
          Problem specs.