code: async def get_mailbox(self, name: str, selected: SelectedMailbox = None) \
              -> Tuple[MailboxInterface, Optional[SelectedMailbox]]:
          
          ...
docs: Retrieves a :class:`~pymap.interfaces.mailbox.MailboxInterface`
          object corresponding to an existing mailbox owned by the user. Raises
          an exception if the mailbox does not yet exist.
  
          Args:
              name: The name of the mailbox.
              selected: If applicable, the currently selected mailbox name.
  
          Raises:
              :class:`~pymap.exceptions.MailboxNotFound`