new_contents: from sqlalchemy import sql
  from sqlalchemy import orm
  
  from .model import MimeMajor
  from .model import Mime
  
  def fetch_mime(dbsession, major, minor):
      cond = sql.and_(
          MimeMajor.name == major,
          Mime.name == minor
      )
  
      result = dbsession.execute(
          sql.select(Mime).join(Mime.major).options(
              orm.contains_eager(Mime.major)
          ).filter(cond)
      ).scalar_one_or_none()
  
      return result
  
subject: add missing module