code: def __str__(self):
      # trying to align to the filename of Qlib: day, 30min, 5min, 1min...
      return f"{self.count if self.count != 1 or self.base != 'day' else ''}{self.base}"
  
imports: import bisect
  from datetime import datetime, time, date, timedelta
  from typing import List, Optional, Tuple, Union
  import functools
  import re
  import pandas
  from qlib.config import C
  from qlib.constant import REG_CN, REG_TW, REG_US
label_desc: Use image node_id 3 for calling the Freq obj's underlying member method code with example usage: obj.__str__() and returns: unknown, self