moto/scripts/template/lib/models.py.j2

from __future__ import unicode_literals
import boto3
from moto.core import BaseBackend, BaseModel


class {{ service_class }}Backend(BaseBackend):
    def __init__(self, region_name=None):
        super({{ service_class }}Backend, self).__init__()
        self.region_name = region_name

    def reset(self):
        region_name = self.region_name
        self.__dict__ = {}
        self.__init__(region_name)

    # add methods from here


available_regions = boto3.session.Session().get_available_regions("{{ service }}")
{{ escaped_service }}_backends = {region: {{ service_class }}Backend(region) for region in available_regions}