docs: public List<Issue> getGroupIssues(Object groupIdOrPath, Integer milestoneId) throws GitLabApiException {
          Response response = get(Response.Status.OK, getDefaultPerPageParam(),
                  "groups", getGroupIdOrPath(groupIdOrPath), "milestones", milestoneId, "issues");
          return (response.readEntity(new GenericType<List<Issue>>() {}));
      }