Move JointTrajectoryPointQueue to private section

Signed-off-by: Carlos San Vicente <carlos.svic@gmail.com>

Author: carlossvg

minimal_data_sharing/minimal_lock_free_queue.cpp

@@ -58,9 +58,6 @@ class TrajectoryGenerator : public rclcpp::Node
 class TrajectoryController : public rclcpp::Node
 {
 public:
-  using JointTrajectoryPointQueue =
-    iox::concurrent::LockFreeQueue<trajectory_msgs::msg::JointTrajectoryPoint, 100>;
-
   TrajectoryController()
   : Node("trajectory_controller")
   {
@@ -107,6 +104,8 @@ class TrajectoryController : public rclcpp::Node
   }
 
 private:
+  using JointTrajectoryPointQueue =
+      iox::concurrent::LockFreeQueue<trajectory_msgs::msg::JointTrajectoryPoint, 100>;
   rclcpp::TimerBase::SharedPtr timer_;
   rclcpp::Subscription<trajectory_msgs::msg::JointTrajectory>::SharedPtr subscription_;
   JointTrajectoryPointQueue queue_;