code: def test_create_should_raise_error_on_both_client_and_url():
      real_client = pymongo.MongoClient()
      with pytest.raises(
          ValueError, match="Cannot pass both a client and a url."
      ):
          MongoObserver(client=real_client, url="mymongourl")
  
imports: import datetime
  import os
  import sys
  from glob import glob
  import mock
  import pytest
  from sacred.metrics_logger import ScalarMetricLogEntry, linearize_metrics
  import gridfs
  from mongomock.gridfs import enable_gridfs_integration
  from .failing_mongo_mock import FailingMongoClient
  from sacred.dependencies import get_digest
  from sacred.observers.mongo import MongoObserver, force_bson_encodeable
label_desc: Use image node_id 2 for calling a global function with example usage: test_create_should_raise_error_on_both_client_and_url() without return types