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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 crypter(self):
 """The actual keyczar crypter"""

        if not hasattr(self, '_crypter'):
            # initialise the Keyczar keysets
            if not self.keyset_location:
                raise ValueError('No encrypted keyset location!')
            reader = keyczar.readers.CreateReader(self.keyset_location)
            if self.encrypting_keyset_location:
                encrypting_keyczar = keyczar.Crypter.Read(
                    self.encrypting_keyset_location)
                reader = keyczar.readers.EncryptedReader(reader,
                                                         encrypting_keyczar)
            self._crypter = keyczar.Crypter(reader)
        return self._crypter