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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 GetCacheSize(self):
 """Determines the size of the uncompressed cached data. Returns: int: number of cached bytes. """

    if not self._cache_start_offset or not self._cache_end_offset:
      return 0
    return self._cache_end_offset - self._cache_start_offset