text: from typing import Optional
  
  from backend.common.models.account import Account
  from backend.common.queries.database_query import DatabaseQuery
  from backend.common.tasklets import typed_tasklet
  
  
  class AccountQuery(DatabaseQuery[Optional[Account]]):
      @typed_tasklet
      def _query_async(self, email: str) -> Optional[Account]:
          if not email:
              return None
          return (yield Account.query(Account.email == email).get_async())
  