def traverse_service(type_context, service_proto, visitor):
    """Traverse a service definition.

    Args:
        type_context: type_context.TypeContext for service type.
        service_proto: ServiceDescriptorProto for service.
        visitor: visitor.Visitor defining the business logic of the plugin.

    Returns:
        Plugin specific output.
    """
    return visitor.visit_service(service_proto, type_context)