docs: private ConfigurationRequest getConfigurationRequest(Map<String, String> userNames) {
          ConfigurationRequest configurationRequest = new ConfigurationRequest();
          configurationRequest.addField(new TextField("sender",
                  "Sender",
                  "graylog@example.org",
                  "The sender of sent out mail alerts",
                  ConfigurationField.Optional.OPTIONAL));
  
          configurationRequest.addField(new TextField("subject",
                  "E-Mail Subject",
                  "Graylog alert for stream: ${stream.title}: ${check_result.resultDescription}",
                  "The subject of sent out mail alerts",
                  ConfigurationField.Optional.NOT_OPTIONAL));
  
          configurationRequest.addField(new TextField("body",
                  "E-Mail Body",
                  FormattedEmailAlertSender.bodyTemplate,
                  "The template to generate the body from",
                  ConfigurationField.Optional.OPTIONAL,
                  TextField.Attribute.TEXTAREA));
  
          configurationRequest.addField(new ListField(CK_USER_RECEIVERS,
                  "User Receivers",
                  Collections.emptyList(),
                  userNames,
                  "Graylog usernames that should receive this alert",
                  ConfigurationField.Optional.OPTIONAL));
  
          configurationRequest.addField(new ListField(CK_EMAIL_RECEIVERS,
                  "E-Mail Receivers",
                  Collections.emptyList(),
                  Collections.emptyMap(),
                  "E-Mail addresses that should receive this alert",
                  ConfigurationField.Optional.OPTIONAL,
                  ListField.Attribute.ALLOW_CREATE));
  
          return configurationRequest;
      }