code: def get_xcom_entry(
      *,
      dag_id: str,
      task_id: str,
      dag_run_id: str,
      xcom_key: str,
      map_index: int = -1,
      deserialize: bool = False,
      session: Session = NEW_SESSION,
  ) -> APIResponse:
      """Get an XCom entry."""
      if deserialize:
          if not conf.getboolean(
              "api", "enable_xcom_deserialize_support", fallback=False
          ):
              raise BadRequest(
                  detail="XCom deserialization is disabled in configuration."
              )
          query = select(XCom, XCom.value)
      else:
          query = select(XCom)
  
      query = query.where(
          XCom.dag_id == dag_id,
          XCom.task_id == task_id,
          XCom.key == xcom_key,
          XCom.map_index == map_index,
      )
      query = query.join(
          DR, and_(XCom.dag_id == DR.dag_id, XCom.run_id == DR.run_id)
      )
      query = query.where(DR.run_id == dag_run_id)
  
      if deserialize:
          item = session.execute(query).one_or_none()
      else:
          item = session.scalars(query).one_or_none()
  
      if item is None:
          raise NotFound("XCom entry not found")
  
      if deserialize:
          xcom, value = item
          stub = copy.copy(xcom)
          stub.value = value
          stub.value = XCom.deserialize_value(stub)
          item = stub
  
      return xcom_schema.dump(item)
  
file_path: airflow/airflow/api_connexion/endpoints/xcom_endpoint.py
imports: from __future__ import annotations
  import copy
  from typing import TYPE_CHECKING
  from flask import g
  from sqlalchemy import and_, select
  from airflow.api_connexion import security
  from airflow.api_connexion.exceptions import BadRequest, NotFound
  from airflow.api_connexion.parameters import check_limit, format_parameters
  from airflow.api_connexion.schemas.xcom_schema import XComCollection, xcom_collection_schema, xcom_schema
  from airflow.auth.managers.models.resource_details import DagAccessEntity
  from airflow.models import DagRun, XCom
  from airflow.settings import conf
  from airflow.utils.db import get_query_count
  from airflow.utils.session import NEW_SESSION, provide_session
  from airflow.www.extensions.init_auth_manager import get_auth_manager
label_desc: Use image node_id 2 for calling a global function with example usage: get_xcom_entry() and returns: xcom_schema