'This block is not bound to a user but some blocks (LibraryContentModule) may need
user-specific services to check for permissions, etc.
If we return None here, CombinedSystem will load services from the descriptor runtime.'

def service(self, block, service_name):

    if (block.service_declaration(service_name) is not None):
        if (service_name == 'user'):
            return DjangoXBlockUserService(self._user)
        if (service_name == 'studio_user_permissions'):
            return StudioPermissionsService(self._user)
        if (service_name == 'settings'):
            return SettingsService()
        if (service_name == 'lti-configuration'):
            return ConfigurationService(CourseEditLTIFieldsEnabledFlag)
    return None
