code: def epoch_ms_to_dttm(cls) -> str:
      return (
          "TO_DATE('1970-01-01','YYYY-MM-DD')+(1/24/60/60/1000)*{col}"
      )
  
file_path: superset/superset/db_engine_specs/oracle.py
imports: from datetime import datetime
  from typing import Any, Optional
  from sqlalchemy import types
  from superset.constants import TimeGrain
  from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod
label_desc: Use image node_id 3 for calling the OracleEngineSpec obj's underlying member method code with example usage: obj.epoch_ms_to_dttm(cls) and returns: str