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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 _document_root(self, fully_qualified=True):
 """ Return the mets Element for the document root. """

        nsmap = {"xsi": utils.NAMESPACES["xsi"], "xlink": utils.NAMESPACES["xlink"]}
        if fully_qualified:
            nsmap["mets"] = utils.NAMESPACES["mets"]
        else:
            nsmap[None] = utils.NAMESPACES["mets"]
        attrib = {
            "{}schemaLocation".format(utils.lxmlns("xsi")): utils.SCHEMA_LOCATIONS
        }
        if self.objid:
            attrib["OBJID"] = self.objid
        return etree.Element(utils.lxmlns("mets") + "mets", nsmap=nsmap, attrib=attrib)