def _out(self, stream, page=None):
        """ Stores the pdf code in a buffer. If it is page related,
            provide the page object.

        """
        if page is not None:
            page.buffer += str(stream) + "\n"
        else:
            self.buffer += str(stream) + "\n"
Stores the pdf code in a buffer. If it is page related,
            provide the page object.