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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 get_certificate(self, filename):
 """ Return a X.509 certificate object by giving the name in the apk file :param filename: filename of the signature file in the APK :returns: a :class:`Certificate` certificate """

        cert = self.get_certificate_der(filename)
        certificate = x509.Certificate.load(cert)

        return certificate