Help With Pure Pursuit Implementation

Hello,
I was working on a pure pursuit controller from this paper:

I wanted to know if anyone had any luck implementing it and would be able to help me out. I am struggling to understand the rate limit and the way it is used throughout the follow. Here is the code for reference:

The code will not run due to an error with the Rate Limit but I have no clue how to implement that in order to remove the error. Any help in advance would be greatly appreciated. \

Thanks,
Aditya