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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 _create_popup_window(title, body):
 """ Return the layout for a pop-up window. It consists of a title bar showing the `title` text, and a body layout. The window is surrounded by borders. """

    assert isinstance(title, six.text_type)
    assert isinstance(body, Container)
    return Frame(body=body, title=title)