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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def UpdateChainAndProcess(self, parser_mediator, registry_key, **kwargs):
 """Updates the parser chain and processes a Windows Registry key or value. Args: parser_mediator (ParserMediator):
 mediates interactions between parsers and other components, such as storage and dfvfs. registry_key (dfwinreg.WinRegistryKey):
 Windows Registry key. Raises: ValueError: If the Windows Registry key is not set. """

    parser_mediator.AppendToParserChain(self)
    try:
      self.Process(parser_mediator, registry_key, **kwargs)
    finally:
      parser_mediator.PopFromParserChain()