docs: def from_db(cls, db, force=False):
          """Make instance from database.
  
          For performance, this caches the episode types for the database.  The
          `force` parameter can be used to bypass this.
  
          """
          if force or db not in cls._cache:
              cls._cache[db] = cls._new_from_db(db)
          return cls._cache[db]