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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 render_long_description(self, dirname):
 """Convert a package's long description to HTML. """

        with changedir(dirname):
            self.setuptools.check_valid_package()
            long_description = self.setuptools.get_long_description()
            outfile = abspath('.long-description.html')
            self.docutils.publish_string(long_description, outfile, self.styles)
            return outfile