code: def get_or_create(session_uuid: str):
      battery_key = BatteryIndex.get(session_uuid)
  
      if not battery_key:
          b = BatteryModel()
          b.save()
          BatteryIndex.set(session_uuid, b.key)
  
          bp = BatteryPreferencesModel()
          bp.save()
          BatteryPreferencesIndex.set(session_uuid, bp.key)
  
          return BatteryAnalysis(b)
  
      return BatteryAnalysis(battery_key.load())
  
imports: from typing import Dict, Any
  from fastapi import Request
  from fastapi.responses import JSONResponse
  from labml_db import Model, Index
  from labml_db.serializer.pickle import PickleSerializer
  from labml_app.logger import logger
  from labml_app.enums import COMPUTEREnums
  from ..analysis import Analysis
  from ..series import SeriesModel, Series
  from ..series_collection import SeriesCollection
  from ..preferences import Preferences
label_desc: Use image node_id 4 for calling the BatteryAnalysis obj's underlying member method code with example usage: obj.get_or_create(session_uuid) and returns: BatteryAnalysis, BatteryAnalysis