def get_model_identifier(model):
    """Returns a model identifier string like : app.Model

    Tests:
        >>> get_model_identifier(AlgoliaIndex)
        'algolia.AlgoliaIndex'

        >>> from django.contrib.auth.models import User
        >>> get_model_identifier(User)
        'auth.User'

        >>> get_model_identifier(object)
        Traceback (most recent call last):
        AttributeError: type object 'object' has no attribute '_meta'

        >>> get_model_identifier()
        Traceback (most recent call last):
        TypeError: get_model_identifier() takes exactly 1 argument (0 given)
    """
    return '{0}.{1}'.format(model._meta.app_label, model.__name__)