code: def test_plugin_registration():
      tracking_store = TrackingStoreRegistry()
  
      test_uri = "mock-scheme://fake-host/fake-path"
      test_scheme = "mock-scheme"
  
      mock_plugin = mock.Mock()
      tracking_store.register(test_scheme, mock_plugin)
      assert test_scheme in tracking_store._registry
      assert (
          tracking_store.get_store(test_uri) == mock_plugin.return_value
      )
      mock_plugin.assert_called_once_with(
          store_uri=test_uri, artifact_uri=None
      )
  
imports: import io
  import itertools
  import os
  import pickle
  from importlib import reload
  from pathlib import Path
  from unittest import mock
  import pytest
  import mlflow
  from mlflow.environment_variables import MLFLOW_TRACKING_INSECURE_TLS, MLFLOW_TRACKING_PASSWORD, MLFLOW_TRACKING_TOKEN, MLFLOW_TRACKING_URI, MLFLOW_TRACKING_USERNAME
  from mlflow.exceptions import MlflowException
  from mlflow.store.db.db_types import DATABASE_ENGINES
  from mlflow.store.tracking.file_store import FileStore
  from mlflow.store.tracking.rest_store import RestStore
  from mlflow.store.tracking.sqlalchemy_store import SqlAlchemyStore
  from mlflow.tracking._tracking_service.registry import TrackingStoreRegistry
  from mlflow.tracking._tracking_service.utils import _get_store, _resolve_tracking_uri, get_tracking_uri, set_tracking_uri
  from mlflow.tracking.registry import UnsupportedModelRegistryStoreURIException
  from mlflow.utils.file_utils import path_to_local_file_uri
  from mlflow.utils.os import is_windows
label_desc: Use image node_id 16 for calling a global function with example usage: test_plugin_registration() without return types