'Modifies the certificate used by the client.
This action can potentially start a workflow to install the
new certificate on the client\'s HSMs.
:type client_arn: string
:param client_arn: The ARN of the client.
:type certificate: string
:param certificate: The new certificate for the client.'

def modify_luna_client(self, client_arn, certificate):

    params = {'ClientArn': client_arn, 'Certificate': certificate}
    return self.make_request(action='ModifyLunaClient', body=json.dumps(params))
