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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 rst2html(rst_src, **kwargs):
 """ Convert a reStructuredText string into a unicode HTML fragment. For `kwargs`, see `default_rst_opts` and http://docutils.sourceforge.net/docs/user/config.html """

    pub = rst2pub(rst_src, settings_overrides=kwargs, writer_name='html')
    return pub.writer.parts['body']