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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 parse(cls, root):
 """ Create a new SubSection by parsing root. :param root: Element or ElementTree to be parsed into an object. :raises exceptions.ParseError: If root's tag is not in :const:`SubSection.ALLOWED_SUBSECTIONS`. :raises exceptions.ParseError: If the first child of root is not mdRef or mdWrap. """

        subsection = root.tag.replace(utils.lxmlns("mets"), "", 1)
        if subsection not in cls.ALLOWED_SUBSECTIONS:
            raise exceptions.ParseError(
                "SubSection can only parse elements with tag in %s with METS namespace"
                % (cls.ALLOWED_SUBSECTIONS,)
            )
        section_id = root.get("ID")
        created = root.get("CREATED", "")
        status = root.get("STATUS", "")
        child = root[0]
        if child.tag == utils.lxmlns("mets") + "mdWrap":
            mdwrap = MDWrap.parse(child)
            obj = cls(subsection, mdwrap, section_id)
        elif child.tag == utils.lxmlns("mets") + "mdRef":
            mdref = MDRef.parse(child)
            obj = cls(subsection, mdref, section_id)
        else:
            raise exceptions.ParseError(
                "Child of %s must be mdWrap or mdRef" % subsection
            )
        obj.created = created
        obj.status = status
        return obj