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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 serialize_to_display(self, xslt_url=None):
 """Serialize to a pretty printed Unicode str, suitable for display. Args: xslt_url: url Optional link to an XSLT stylesheet. If provided, a processing instruction for the stylesheet is included in the XML prolog. """

        return d1_common.xml.serialize_to_xml_str(
            self.get_pyxb(), pretty=True, xslt_url=xslt_url
        )