Minor change to have homogeneous typedef before introducing std::set

include/core/trajectory/trajectory_base.h

@@ -23,7 +23,7 @@ class TrajectoryBase : public NodeBase, public std::enable_shared_from_this<Traj
     friend FrameBase;
 
     private:
-        std::list<FrameBasePtr> frame_list_;
+        FrameBasePtrList frame_list_;
 
     protected:
         std::string frame_structure_;  // Defines the structure of the Frames in the Trajectory.