Return the list of all available resources on the system.

        Resources are filtered according to the permission system, so querying
        this resource as different users may bare different results.

def resource_listing(cls, request) -> [(200, 'Ok', ResourceListingModel)]:
        '''Return the list of all available resources on the system.

        Resources are filtered according to the permission system, so querying
        this resource as different users may bare different results.'''
        apis = [api.get_swagger_fragment() for api in Api if not api.private]
        Respond(200, {
            'apiVersion': cls.api.version,
            'swaggerVersion': cls.api.swagger_version,
            'apis': apis
        })