rlm_sim_files pairadd only ? Is there any need to pairdelete ?

I am fairly new to writing modules for freeradius. While reading the sources for rlm_sim_files, in the authorize section the code adds the needed attributes by using pairadd(...). I am just wondering if the authorize section keeps adding things into the memory by using pairadd(), at some point in time ( say after authentication ) these values will have to be removed from the memory, otherwise after many times of invocations, that will constitute a memory leak. How is the housekeeping been carried out ?