code: def is_cache(cache):
      
      if isinstance(cache, string_types + FILE_LIKE):
          try:
              return bool(len(read_cache(cache)))
          except (TypeError, ValueError, UnicodeDecodeError, ImportError):
              # failed to parse cache
              return False
      if HAS_CACHE and isinstance(cache, Cache):
          return True
      if (isinstance(cache, (list, tuple)) and cache and
              all(map(is_cache_entry, cache))):
          return True
  
      return False
docs: Returns `True` if ``cache`` is a readable cache file or object
  
      Parameters
      ----------
      cache : `str`, `file`, `list`
          Object to detect as cache
  
      Returns
      -------
      iscache : `bool`
          `True` if the input object is a cache, or a file in LAL cache format,
          otherwise `False`