Renders the frame on the line after clearing it.

def _render_frame(self):
        """Renders the frame on the line after clearing it.
        """
        frame = self.frame()
        output = '\r{0}'.format(frame)
        self.clear()
        try:
            self._stream.write(output)
        except UnicodeEncodeError:
            self._stream.write(encode_utf_8_text(output))