docs: def load_cache(self):
          """Load the cached Zotero data."""
          with open(self.cache_path, "rb") as f:
              print("Loading cached Zotero data...")
              cache = pickle.load(f)
              self._references = cache[self.CACHE_REFERENCE_LIST]
              self.reference_types = cache[self.CACHE_REFERENCE_TYPES]
              self.reference_templates = cache[self.CACHE_REFERENCE_TEMPLATES]
              print("Cached Zotero data loaded.")