code: def to_ds(ts: datetime) -> str:
      """Convert a `datetime` to a DS string."""
      return datetime.strftime(ts, DS_FRMT)
  
file_path: Ax/ax/utils/common/timeutils.py
imports: from datetime import datetime, timedelta
  from time import time
  from typing import Generator
  import pandas
label_desc: Use image node_id 1 for calling a global function with example usage: to_ds(ts) and returns: datetime