# Problem

the functools.lru_cache decorator locks all arguments to the function in memory (inclusing self), causing hard to find memory leaks. 

# Expected  

I had assumed that the lru_cache would keep weak-references and that when an object is garbage colected, all its cache entries expire as unreachable. This is not the case.

# Solutions 

1. I think it is worth at least mentioning this behavior in de documentation. 
2. I also think it would be good if the LRU cache actually uses weak references. 

I will try to make a PR for this.