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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 _read_xml_file(self):
 """ read metadata from an xml file. :return: the root element of the xml :rtype: ElementTree.Element """

        # this raises a IOError if the file doesn't exist
        root = ElementTree.parse(self.xml_uri)
        root.getroot()
        return root