How to measure the time between the client and server

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Hello everyone,

I am trying to measure the time it takes till the server is executed by the client.

I added the rospy.loginfo(rospy.get_caller_id()) to the add_two_ints_server, and it works as expected. However the client script does not recognize the command I want to run, that's why I cannot obtain the information I want.

rospy.get_time() command also doesn't work. Can someone please help me to get the WallTime info in add_two_ints_client.py?