def importExistingServerCertificate(self, alias, certPassword, certFile):
        """This operation imports an existing server certificate, stored in the PKCS #12 format, into the keystore."""
        url = self._url + "/sslcertificates/importExistingServerCertificate"
        files = {}
        files['certFile'] = certFile
        params = {
            "f" : "json",
            "alias" : alias,
            "certPassword" : certPassword
        }
        return self._post(url=url,
                            param_dict=params,
                            securityHandler=self._securityHandler,
                            files=files,
                            proxy_url=self._proxy_url,
                            proxy_port=self._proxy_port)