def plan_point_cluster_grasp_callback(self, req):
     rospy.loginfo("planning grasps for a point cluster")
     resp = GraspPlanningResponse()        
     (grasps, error_code) = self.plan_point_cluster_grasps(req.target, req.arm_name)
     resp.grasps = grasps
     resp.error_code = error_code
     return resp