eZ\Publish\Core\REST\Server\Controller\User::loadUsers PHP Method

    public function loadUsers(Request $request)
    {
        $restUsers = array();
        try {
            if ($request->query->has('roleId')) {
                $restUsers = $this->loadUsersAssignedToRole($this->requestParser->parseHref($request->query->get('roleId'), 'roleId'));
            } elseif ($request->query->has('remoteId')) {
                $restUsers = array($this->buildRestUserObject($this->userService->loadUser($this->contentService->loadContentInfoByRemoteId($request->query->get('remoteId'))->id)));
            } elseif ($request->query->has('login')) {
                $restUsers = array($this->buildRestUserObject($this->userService->loadUserByLogin($request->query->get('login'))));
            } elseif ($request->query->has('email')) {
                foreach ($this->userService->loadUsersByEmail($request->query->get('email')) as $user) {
                    $restUsers[] = $this->buildRestUserObject($user);
                }
            }
        } catch (ApiExceptions\UnauthorizedException $e) {
            $restUsers = [];
        }
        if (empty($restUsers)) {
            throw new NotFoundException('No users were found with the given filter');
        }
        if ($this->getMediaType($request) === 'application/vnd.ez.api.userlist') {
            return new Values\UserList($restUsers, $request->getPathInfo());
        }
        return new Values\UserRefList($restUsers, $request->getPathInfo());
    }