Override of ``lxml`` _Element.xpath() method to provide standard Open
        XML namespace mapping (``nsmap``) in centralized location.

def xpath(self, xpath_str):
        """
        Override of ``lxml`` _Element.xpath() method to provide standard Open
        XML namespace mapping (``nsmap``) in centralized location.
        """
        return super(BaseOxmlElement, self).xpath(
            xpath_str, namespaces=nsmap
        )