def find(self, title):
        """Return the first worksheet with the given title.

        Args:
            title(str): title/name of the worksheet to return
        Returns:
            WorkSheet: contained worksheet object
        Raises:
            KeyError: if the spreadsheet has no no worksheet with the given ``title``
        """
        if title not in self._titles:
            raise KeyError(title)
        return self._titles[title][0]