code: def _extract_mlflow_response_key(response):
      if MLFLOW_SERVING_RESPONSE_KEY not in response:
          raise HTTPException(
              status_code=502,
              detail=f"The response is missing the required key: {MLFLOW_SERVING_RESPONSE_KEY}.",
          )
      return response[MLFLOW_SERVING_RESPONSE_KEY]
  
imports: import time
  from typing import List
  from fastapi import HTTPException
  from fastapi.encoders import jsonable_encoder
  from pydantic import BaseModel, StrictFloat, StrictStr, ValidationError, validator
  from mlflow.gateway.config import MlflowModelServingConfig, RouteConfig
  from mlflow.gateway.constants import MLFLOW_SERVING_RESPONSE_KEY
  from mlflow.gateway.providers.base import BaseProvider
  from mlflow.gateway.providers.utils import send_request
  from mlflow.gateway.schemas import chat, completions, embeddings
label_desc: Use image node_id 2 for calling the MlflowModelServingProvider obj's underlying member method code with example usage: obj._extract_mlflow_response_key(response) and returns: response