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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 text(self, text, stylename=None):
 """Add text within the current container."""

        assert self._containers
        container = self._containers[-1]
        if stylename is not None:
            stylename = self._get_style_name(stylename)
            container.addElement(Span(stylename=stylename, text=text))
        else:
            container.addElement(Span(text=text))