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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 strip_html(self, doc):
 """ This method removes all HTML from a docstring. Lighter than ``convert_docs``, this is intended for the documentation on **parameters**, not the overall docs themselves. :param doc: The initial docstring :type doc: string :returns: The stripped/cleaned docstring :rtype: string """

        if not isinstance(doc, six.string_types):
            return ''

        doc = doc.strip()
        doc = self.tag_re.sub('', doc)
        return doc