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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 display_popup(self, title, content):
 """ Display a pop-up dialog. """

        assert isinstance(title, six.text_type)
        assert isinstance(content, six.text_type)

        self.popup_dialog.title = title
        self._popup_textarea.text = content
        self.client_state.display_popup = True
        get_app().layout.focus(self._popup_textarea)