Comment update

src/python/cache_utils.py

@@ -1,11 +1,8 @@
 #!/usr/bin/env python3
-""" Contains all the functions related to the caches. 
-TODO: Elsewhere, the code speaks of "the cache" (example: get_cache_lock), but here it speaks of 4 caches. I'm confused about the relationship.
-TODO: Are there 4 caches overall, or 4 caches per repository, or something else? Please clarify.
-TODO: "after running the script": Which script?
-There will be 4 caches which are stored on disk after running the script:
-TODO: Is the cache directory literally named "cache"?  Where is it on disk?
-TODO: Are all the caches JSON files?
+""" Contains all the functions related to the caches. The functions to interact with each
+of the caches are in this file. Each cache is interacted with through the functions 
+of this file. The caches are all JSON files and are stored in the cache directory.
+There will be 4 caches in total which are stored on disk after running the run.sh script:
 1) cache/sha_cache_entry:  A cache that maps the commit hash to a sha256 hash of the repository.
 2) cache/test_cache: A cache that maps a sha256 to test results.
 3) cache/merge_results:A cache that maps a merge to the result