def get_base_url(use_prod=False):
    """Returns the base url, either sandbox or prod.
    @param use_prod: use production url or sandbox.
    """
    if use_prod:
        service_url = "https://api.emailage.com/EmailAgeValidator/"
    else:
        service_url = "https://sandbox.emailage.com/EmailAgeValidator/"  # Sandbox
    return service_url