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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 decodedFileID(self, cachedFilePath):
 """ Decode a cached fileName back to a job store file ID. :param str cachedFilePath: Path to the cached file :return: The jobstore file ID associated with the file :rtype: str """

        fileDir, fileName = os.path.split(cachedFilePath)
        assert fileDir == self.localCacheDir, 'Can\'t decode uncached file names'
        # We encode and decode here because base64 can't work with unencoded text
        # Its probably worth, later, converting all file name variables to bytes
        # and not text.
        return base64.urlsafe_b64decode(fileName.encode('utf-8')).decode('utf-8')