code: def get_in_seg_vlan(cls, tenant_id):
          
          if tenant_id not in cls.serv_obj_dict:
              LOG.error("Fabric not prepared for tenant %s", tenant_id)
              return None, None
          tenant_obj = cls.serv_obj_dict.get(tenant_id)
          return tenant_obj.get_in_seg_vlan()
docs: Retrieves the IN Seg, VLAN, mob domain.