Test::LeakTrace provides several functions that trace memory leaks. This module
scans arenas, the memory allocation system, so it can detect any leaked SVs in
Leaked SVs are SVs that are not released after the end of the scope they have
been created. These SVs include global variables and internal caches. For
example, if you call a method in a tracing block, perl might prepare a cache
for the method. Thus, to trace true leaks, no_leaks_ok() and leaks_cmp_ok()
executes a block more than once.