async def METHOD_NAME(self, auth, headers):
    """ method to set splunk auth token """
    data = {'username': auth['username'], 'password': auth['password'], 'output_mode': 'json'}
    endpoint = self.endpoint_start + 'auth/login'
    try:
        data = await self.client.call_api(endpoint, 'POST', headers, data=data, timeout=self.timeout)
        response_json = json.load(data)
        headers['Authorization'] = "Splunk " + response_json['sessionKey']
    except KeyError as e:
        raise Exception('Authentication error occured while getting auth token: ' + str(e))