docs: def _lookup(key):
      """
      Internal method that looks up a key in the local cache.
      :param key: Get the value based on the key from the cache.
      :type key: string
      :returns: void
      """
      if key not in _CACHE:
          return None
      if _CACHE_COUNTER[key] >= len(_CACHE[key][1:]):
          if _CACHE[key][0] == "empty":
              return ""
          elif _CACHE[key][0] == "repeat" and _CACHE[key][1:]:
              return _CACHE[key][-1]
          elif _CACHE[key][0] == "repeat":
              return ""
          else:
              _CACHE_COUNTER[key] = 1
      else:
          _CACHE_COUNTER[key] += 1
      if _CACHE[key]:
          return _CACHE[key][_CACHE_COUNTER[key]]
      else:
          return ""