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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 title(self, gender: Optional[Gender] = None, title_type: Optional[TitleType] = None) -> str: """Generate a random title for name. You can generate random prefix or suffix for name using this method. :param gender: The gender. :param title_type: TitleType enum object. :return: The title. :raises NonEnumerableError: if gender or title_type in incorrect format. :Example: PhD. """

        gender_key = self._validate_enum(gender, Gender)
        title_key = self._validate_enum(title_type, TitleType)

        titles = self._data['title'][gender_key][title_key]
        return self.random.choice(titles)