Create a "one-shot" ``_RunContentAppender`` instance and use it to
        append the run content elements corresponding to *text* to the
        ``<w:r>`` element *r*.

def append_to_run_from_text(cls, r, text):
        """
        Create a "one-shot" ``_RunContentAppender`` instance and use it to
        append the run content elements corresponding to *text* to the
        ``<w:r>`` element *r*.
        """
        appender = cls(r)
        appender.add_text(text)