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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 inline_css(html_message, encoding='unicode'):
 """ Inlines all CSS in an HTML string Given an HTML document with CSS declared in the HEAD, inlines it into the applicable elements. Used primarily in the preparation of styled emails. Arguments: html_message -- a string of HTML, including CSS """


    document = etree.HTML(html_message)
    converter = Conversion()
    converter.perform(document, html_message, '', encoding=encoding)
    return converter.convertedHTML