code: def _get_s(cls, df, column, shifts):
          
          shift = cls.to_int(shifts)
          shifted_key = "{}_{}_s".format(column, shift)
          df[shifted_key] = df[column].shift(-shift)
          StockDataFrame.set_nan(df[shifted_key], shift)
docs: Get the column shifted by days
  
          :param df: DataFrame object
          :param column: name of the column to shift
          :param shifts: days to shift, accept one shift only
          :return: None