private DataFetcher projectAuthorizationsFetcher() { return fetcher( Project.class, (environment, project) -> rolesService.getProjectRoles().stream() .filter(GraphqlUtils.getStringArgument(environment, "role") .map(s -> (Predicate<ProjectRole>) pr -> StringUtils.equals(s, pr.getId())) .orElseGet(() -> pr -> true)) .map(projectRole -> getProjectAuthorizations(project, projectRole)) .collect(Collectors.toList()) ); }