docs: def load_and_print_resfile(filename, info_dict=None):
      """Load a raw data file and print information.
  
      Args:
          filename (str): name of the resfile.
          info_dict (dict):
  
      Returns:
          info (str): string describing something.
      """
  
      # self.test_no = None
      # self.mass = 1.0  # mass of (active) material (in mg)
      # self.no_cycles = 0.0
      # self.charge_steps = None  # not in use at the moment
      # self.discharge_steps = None  # not in use at the moment
      # self.ir_steps = None  # dict # not in use at the moment
      # self.ocv_steps = None  # dict # not in use at the moment
      # self.nom_cap = 3579  # mAh/g (used for finding c-rates)
      # self.mass_given = False
      # self.c_mode = True
      # self.starts_with = "discharge"
      # self.material = "noname"
      # self.merged = False
      # self.file_errors = None  # not in use at the moment
      # self.loaded_from = None  # name of the .res file it is loaded from
      # (can be list if merged)
      # self.raw_data_files = []
      # self.raw_data_files_length = []
      # # self.parent_filename = None # name of the .res file it is loaded from
      # (basename) (can be list if merded)
      # # self.parent_filename = if listtype, for file in etc,,,
      # os.path.basename(self.loaded_from)
      # self.channel_index = None
      # self.channel_number = None
      # self.creator = None
      # self.item_ID = None
      # self.schedule_file_name = None
      # self.start_datetime = None
      # self.test_ID = None
      # self.name = None
  
      # NEXT: include nom_cap, tot_mass and  parameters table in save/load hdf5
      if info_dict is None:
          info_dict = dict()
          info_dict["mass"] = 1.23  # mg
          info_dict["nom_cap"] = 3600  # mAh/g (active material)
          info_dict["tot_mass"] = 2.33  # mAh/g (total mass of material)
  
      d = CellpyData()
  
      print("filename:", filename)
      print("info_dict in:", end=' ')
      print(info_dict)
  
      d.from_raw(filename)
      d.set_mass(info_dict["mass"])
      d.make_step_table()
      d.make_summary()
  
      for test in d.datasets:
          print("newtest")
          print(test)
  
      return info_dict