code: def _ensure_updated_strategy_flag_set(
      state_dict: Dict[str, Tensor],
      prefix: str,
      local_metadata: Dict[str, Any],
      strict: bool,
      missing_keys: Iterable[str],
      unexpected_keys: Iterable[str],
      error_msgs: Iterable[str],
  ):
      device = state_dict[list(state_dict.keys())[0]].device
      if prefix + "updated_strategy" not in state_dict:
          state_dict[prefix + "updated_strategy"] = torch.tensor(
              False, device=device
          )
          warnings.warn(
              "You have loaded a variational GP model (using `VariationalStrategy`) from a previous version of "
              "GPyTorch. We have updated the parameters of your model to work with the new version of "
              "`VariationalStrategy` that uses whitened parameters.\nYour model will work as expected, but we "
              "recommend that you re-save your model.",
              OldVersionWarning,
          )
  
imports: import warnings
  from typing import Any, Dict, Iterable, Optional, Tuple
  import torch
  from linear_operator import to_dense
  from linear_operator.operators import CholLinearOperator, DiagLinearOperator, LinearOperator, MatmulLinearOperator, RootLinearOperator, SumLinearOperator, TriangularLinearOperator
  from linear_operator.utils.cholesky import psd_safe_cholesky
  from linear_operator.utils.errors import NotPSDError
  from torch import Tensor
  from gpytorch.variational._variational_strategy import _VariationalStrategy
  from gpytorch.variational.cholesky_variational_distribution import CholeskyVariationalDistribution
  from ..distributions import MultivariateNormal
  from ..models import ApproximateGP
  from ..settings import _linalg_dtype_cholesky, trace_mode
  from ..utils.errors import CachingError
  from ..utils.memoize import cached, clear_cache_hook, pop_from_cache_ignore_args
  from ..utils.warnings import OldVersionWarning
  from .None import _VariationalDistribution
label_desc: Use image node_id 1 for calling a global function with example usage: _ensure_updated_strategy_flag_set(state_dict, prefix, local_metadata, strict, missing_keys, unexpected_keys, error_msgs) without return types