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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 GrabFileSystem(self, path_spec):
 """Grabs a cached file system object defined by path specification. Args: path_spec (PathSpec):
 path specification. """

    identifier = self._GetFileSystemCacheIdentifier(path_spec)
    self._file_system_cache.GrabObject(identifier)