def default_store(database, host, port):
    """Gets a default store for connectable or URL. If store does not exist
    one is created and added to shared default store pool."""

    key = (database, host, port)
    try:
        store = _default_stores[key]
    except __HOLE__:
        store = MongoDBStore(database, host=host, port=port)
        _default_stores[key] = store

    return store
dataset/ETHPy150Open Stiivi/bubbles/bubbles/backends/mongo/objects.py/default_store