Return a newly added ``<w:t>`` element containing *text*.

def add_t(self, text):
        """
        Return a newly added ``<w:t>`` element containing *text*.
        """
        t = self._add_t(text=text)
        if len(text.strip()) < len(text):
            t.set(qn('xml:space'), 'preserve')
        return t