new_contents: """Reference data helpers."""
  
  import json
  import pkgutil
  from mgz.util import Version
  
  
  REF_PACKAGE = 'aocref'
  
  
  def get_dataset(version, mod):
      """Fetch dataset reference data."""
      if version is Version.DE:
          dataset_id = 100
      elif mod:
          dataset_id = mod[0]
      else:
          dataset_id = 0
      return dataset_id, json.loads(pkgutil.get_data(REF_PACKAGE, f'data/datasets/{dataset_id}.json'))
  
  
  def get_consts():
      """Fetch constants."""
      return json.loads(pkgutil.get_data(REF_PACKAGE, f'data/constants.json'))
  
subject: add reference shim