docstr: formatting the datetime in an instrument
  
  Parameters
  ----------
  inst_df: pd.DataFrame
      inst_df.columns = [self.SYMBOL_FIELD_NAME, self.START_DATE_FIELD, self.END_DATE_FIELD]
  
  Returns
  -------
docstr_tok: ["formatting","the","datetime","in","an","instrument","Parameters","--","--","--","--","--","inst_df",":","pd.DataFrame","inst_df.columns","=","[","self.SYMBOL_FIELD_NAME",",","self.START_DATE_FIELD",",","self.END_DATE_FIELD","]","Returns","--","--","--","-"]
code: def format_datetime(self, inst_df: pd.DataFrame) -> pd.DataFrame:
      """formatting the datetime in an instrument
  
      Parameters
      ----------
      inst_df: pd.DataFrame
          inst_df.columns = [self.SYMBOL_FIELD_NAME, self.START_DATE_FIELD, self.END_DATE_FIELD]
  
      Returns
      -------
  
      """
      raise NotImplementedError("rewrite format_datetime")
  
file_path: qlib/scripts/data_collector/index.py
imports: import sys
  import abc
  from pathlib import Path
  from typing import List
  import pandas
  from tqdm import tqdm
  from loguru import logger
  from data_collector.utils import get_trading_date_by_shift
label_desc: Use image node_id 6 for calling the IndexBase obj's underlying member method code with example usage: obj.format_datetime(inst_df) without return types