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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 Decrypt(self, data):
 """A convenience method which pads and decrypts at once."""

    decryptor = self.GetDecryptor()

    try:
      padded_data = decryptor.update(data) + decryptor.finalize()
      return self.UnPad(padded_data)
    except ValueError as e:
      raise CipherError(e)