code: def _prep_fields_param(fields):
      
  
      store_samples = False
  
      if fields is None:
          # add samples by default
          return True, None
  
      if isinstance(fields, str):
          fields = [fields]
      else:
          fields = list(fields)
  
      if 'samples' in fields:
          fields.remove('samples')
          store_samples = True
      elif '*' in fields:
          store_samples = True
  
      return store_samples, fields
docs: Prepare the `fields` parameter, and determine whether or not to store samples.