code: def slice_naive(self, key):
          
          cls = self.__class__
          key = check_key(self, key)
          enum = pd.Series(range(len(self)))
          enum.index = self.index
          values = self.field_values[enum[key].values]
          data = self.loc[key]
          return cls(data, field_values=values)
docs: Naively (on index) slice the field data and values.
  
          Args:
              key: Int, slice, or iterable to select data and values
  
          Returns:
              field: Sliced field object