docs: def notify_deployment(self, application_id=None, application_name=None, description=None, revision=None, changelog=None, user=None):
          """
          Notify NewRelic of a deployment.
          http://newrelic.github.io/newrelic_api/NewRelicApi/Deployment.html
  
          :param description:
          :param revision:
          :param changelog:
          :param user:
          :return: A dictionary containing all of the returned keys from the API
          """
  
          endpoint = "https://rpm.newrelic.com"
          uri = "{endpoint}/deployments.xml".format(endpoint=endpoint)
  
          deploy_event = {}
  
          if not application_id is None:
              deploy_event['deployment[application_id]'] = application_id
          elif not application_name is None:
              deploy_event['deployment[app_name]'] = application_name
          else:
              raise NewRelicInvalidParameterException("Must specify either application_id or application_name.")
  
          if not description is None:
              deploy_event['deployment[description]'] = description
  
          if not revision is None:
              deploy_event['deployment[revision]'] = revision
  
          if not changelog is None:
              deploy_event['deployment[changelog]'] = changelog
  
          if not user is None:
              deploy_event['deployment[user]'] = user
  
          response = self._make_post_request(uri, deploy_event)
          result = {}
  
          for value in response:
              result[value.tag] = value.text
  
          return result