code: def save_calibration(labware: Labware, delta: Point):
      
      calibration_path = CONFIG['labware_calibration_offsets_dir_v4']
      if not calibration_path.exists():
          calibration_path.mkdir(parents=True, exist_ok=True)
      labware_offset_path = calibration_path/'{}.json'.format(labware._id)
      calibration_data = _helper_offset_data_format(
          str(labware_offset_path), delta)
      with labware_offset_path.open('w') as f:
          json.dump(calibration_data, f)
      labware.set_calibration(delta)
docs: Function to be used whenever an updated delta is found for the first well
      of a given labware. If an offset file does not exist, create the file
      using labware id as the filename. If the file does exist, load it and
      modify the delta and the lastModified fields under the "default" key.