def check_dependency(app_name):
    if app_name not in settings.INSTALLED_APPS:
        raise DependencyError(app_name)
An eager relationship can be upgraded to a lazy relationship.
dataset/ETHPy150Open django-erp/django-erp/djangoerp/core/utils/dependencies.py/check_dependency--crossover with--dataset/ETHPy150Open zzzeek/sqlalchemy/test/orm/test_mapper.py/OptionsTest.test_lazy_options