The XCom endpoint joins the XCom and DagRun tables. Currently, the output of the join isn't getting stored as a new `query` variable, as seen in the link to the following PR. We should add a new test to check that these tables are getting joined correctly.

https://github.com/apache/airflow/pull/10594/files/1fe1da978763c9919cee0d2c7eccd96438631993#diff-aa0c2f68c6177fb1587a6de6b5cfb28cR59


I will make these changes after #10594 
tests/api_connexion/endpoints/test_xcom_endpoint.py
#
#
import unittest
from parameterized import parameterized
from airflow.models import DagModel, DagRun as DR, XCom
from airflow.security import permissions
from airflow.utils.dates import parse_execution_date
from airflow.utils.session import provide_session
from airflow.utils.types import DagRunType
from airflow.www import app
from tests.test_utils.api_connexion_utils import assert_401, create_user, delete_user
from tests.test_utils.config import conf_vars
from tests.test_utils.db import clear_db_dags, clear_db_runs, clear_db_xcom
class TestXComEndpoint(unittest.TestCase):