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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 add_voice(self, voices, item):
 """ Adds a voice to the list """

        voice = None
        if item.get('type') == 'title':
            voice = self.get_title_voice(item)
        elif item.get('type') == 'app':
            voice = self.get_app_voice(item)
        elif item.get('type') == 'model':
            voice = self.get_app_model_voice(item)
        elif item.get('type') == 'free':
            voice = self.get_free_voice(item)
        if voice:
            voices.append(voice)