code: def since(timestamp: str) -> datetime:
      try:
          seconds = parse_pretty_duration(timestamp)
          return get_current_datetime() - timedelta(seconds=seconds)
      except ValueError:
          pass
      try:
          return datetime.fromisoformat(timestamp)
      except ValueError:
          pass
      try:
          return datetime.fromtimestamp(int(timestamp))
      except Exception:
          raise ValueError("Invalid datetime format")
  
file_path: dstack/src/dstack/_internal/utils/common.py
imports: import re
  import time
  from datetime import datetime, timedelta, timezone
  from pathlib import Path
  from typing import Optional, Tuple, Union
label_desc: Use image node_id 6 for calling a global function with example usage: since(timestamp) and returns: unknown, datetime, datetime