def titles(self, unique=False):
        """Return a list of contained worksheet titles.

        Args:
            unique (bool): drop duplicates
        Returns:
            list: list of titles/name strings
        """
        if unique:
            return tools.uniqued(s.title for s in self._items)
        return [s.title for s in self._items]
Return a list of contained worksheet titles.

        Args:
            unique (bool): drop duplicates
        Returns:
            list: list of titles/name strings