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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 package_description(self):
 """ Given an Article class instance, this is responsible for returning an article description. For this method I have taken the approach of serializing the article's first abstract, if it has one. This results in 0 or 1 descriptions per article. """

        abstract = self.article.root.xpath('./front/article-meta/abstract')
        return serialize(abstract[0], strip=True) if abstract else None