It is said that bitcoin uses random delay when relaying transaction to other peers in order to protect privacy.But when i'm reading the source code of the newest bitcoin core https://github.com/bitcoin/bitcoin .I found a function called rand_uniform_delay.But when i'm searching its usage,i found it only used in a random_test.cpp . I wonder where is the code about random delay in bitcoin core.  

I read that bitcoin uses random delay when relaying transaction to other peers in order to protect privacy. When I read the source code of the newest Bitcoin Core, I found a function called rand_uniform_delay. When I searched for its usage, I found it only used in random_test.cpp. I wonder where the code for the random delay in Bitcoin Core can be found.