old_contents: #!/usr/bin/env python
  import rospy
  from trajectory_tracking.srv import TrajectoryPoint, TrajectoryPointResponse
  from geometry_msgs.msg import Point
  
  def compute_position(request):
      position = Point()
      position.x = 0.0
      position.y = 1.0
      position.z = 2.0
      return TrajectoryPointResponse(position)
  
  
  if __name__ == '__main__':
      rospy.init_node('trajectory_server')
      service = rospy.Service('trajectory', TrajectoryPoint, compute_position)
      rospy.spin()
  
new_contents: #!/usr/bin/env python
  import rospy
  from trajectory_tracking.srv import TrajectoryPoint, TrajectoryPointResponse
  from geometry_msgs.msg import Point
  
  def compute_position(request):
      position = Point()
      position.x = 0.0
      position.y = 1.0
      position.z = 2.0
      return position
  
  
  if __name__ == '__main__':
      rospy.init_node('trajectory_server')
      service = rospy.Service('trajectory', TrajectoryPoint, compute_position)
      rospy.spin()
  
subject: Refactor return value