def search_manager_from_config(config, **default_init):
    """Get a `SearchManager` instance dynamically based on config.

    `config` is a dictionary containing ``class`` and ``init`` keys as defined
    in :mod:`birding.config`.
    """
    manager_cls = import_name(config['class'], default_ns='birding.search')
    init = {}
    init.update(default_init)
    init.update(config['init'])
    manager = manager_cls(**init)
    return manager