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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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]