Can't find a topic “/detect_grasps/clustered_grasps” publisher

[WwYyFan]

I want to subscribe a topic "/detect_grasps/clustered_grasps",but i can not find the topic publisher my c++ code

void callback(const gpd::GraspConfigList::ConstPtr& msg)
{
    ROS_INFO("testing~~~~~~~~~~");
}

int main(int argc, char *argv[])
{
    ros::init(argc, argv, "grasp_test");
    ros::NodeHandle nh;
    ros::Subscriber sub = nh.subscribe<gpd::GraspConfigList>("/detect_grasps/clustered_grasps",100,callback);
    return 0;
}