code: def get_kbs(custom_kbs_files=None, cache={}):  # noqa
      
  
      cache_key = make_cache_key(custom_kbs_files)
      if cache_key not in cache:
          # Build paths from defaults and specified ones
          kbs_files = CFG_REFEXTRACT_KBS.copy()
          if custom_kbs_files:
              for key, path in custom_kbs_files.items():
                  if path:
                      kbs_files[key] = path
          # Loads kbs from those paths
          cache[cache_key] = load_kbs(kbs_files)
      return cache[cache_key]
docs: Load kbs (with caching).
  
      This function stores the loaded kbs into the cache variable
      For the caching to work, it needs to receive an empty dictionary
      as "cache" paramater.