Remove all child elements except the ``<w:rPr>`` element if present.

def clear_content(self):
        """
        Remove all child elements except the ``<w:rPr>`` element if present.
        """
        content_child_elms = self[1:] if self.rPr is not None else self[:]
        for child in content_child_elms:
            self.remove(child)