class_docstr: This class guarantees that hash() will be called no more than once
  per element.  This is important because the lru_cache() will hash
  the key multiple times on a cache miss.
class_docstr_tok: ["This","class","guarantees","that","hash","(",")","will","be","called","no","more","than","once","per","element",".","This","is","important","because","the","lru_cache","(",")","will","hash","the","key","multiple","times","on","a","cache","miss","."]
code: def __init__(self, tup, hash=hash):
      self[:] = tup
      self.hashvalue = hash(tup)
  
imports: from abc import get_cache_token
  from collections import namedtuple
  from reprlib import recursive_repr
  from _thread import RLock
label_desc: Use image node_id 1 to create a new _HashedSeq object from inherited base classes: list with example: obj = _HashedSeq(tup, hash)