code: public GitlabServiceEmailOnPush getEmailsOnPush(Integer projectId) throws IOException {
          String tailUrl = GitlabProject.URL + "/" + projectId + GitlabServiceEmailOnPush.URL;
          return retrieve().to(tailUrl, GitlabServiceEmailOnPush.class);
      }
docs: Gets email-on-push service setup for a projectId.
  
  @param projectId The ID of the project containing the variable.
  @throws IOException on gitlab api call error