Can I use 'interval fanction'??

[takomon]

Hello,Author!!! I'm using iperf3 funcion.
I'd like to use 'interval function' to check measure speed every few seconds,but I don`t know how to use this function. If I'm able to use 'interval function' or there is 'interval module' to be used iperf3,please tell me how to use them.

Also,I want to ask you one order. If there isn't 'interval function' and I can't use them now, can you add the function to measure speed every few seconds??