serie being trusty, yakkety, xenial, zesty
tag being sts-sru

self.ubuntu = self.lp.distributions['ubuntu'].getSeries(                                                   
    name_or_version=serie)                                                                                 
self.tasks = self.ubuntu.searchTasks(tags=tag,                                                             
                                     created_since=self.start_date,                                        
                                     order_by='id')