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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_default(cls, package):
 """ Create and return a default notes master part, including creating the new theme it requires. """

        notes_master_part = cls._new(package)
        theme_part = cls._new_theme_part(package)
        notes_master_part.relate_to(theme_part, RT.THEME)
        return notes_master_part