code: def by_classifiers(cls, session, classifiers):
          
          return cls.find(session,
                          join=(cls.classifiers,),
                          where=(Classifier.name.in_(classifiers),),
                          )
docs: Get releases for given classifiers.
  
          :param session: SQLAlchemy session
          :type session: :class:`sqlalchemy.Session`
  
          :param classifiers: classifiers
          :type classifiers: unicode
  
          :return: release instances
          :rtype: generator of :class:`pyshop.models.Release`