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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 add_text(self, text):
 """ Add a text node to this element. Adding text with this method is subtly different from assigning a new text value with :meth:`text` accessor, because it "appends" to rather than replacing this element's set of text nodes. :param text: text content to add to this element. :param type: string or anything that can be coerced by :func:`unicode`. """

        if not isinstance(text, basestring):
            text = unicode(text)
        self._add_text(self.impl_node, text)