def get_ca_certificates(self):
if self._cacerts is not None:<EOL><INDENT>return tuple(self._cacerts)<EOL><DEDENT>
Get the CA certificates in the PKCS #12 structure.

:return: A tuple with the CA certificates in the chain, or
    :py:const:`None` if there are none.
:rtype: :py:class:`tuple` of :py:class:`X509` or :py:const:`None`