Return DNN or RNN depending on if relationships are loaded.

def _get_depthsr(self, goobj):
        """Return DNN or RNN depending on if relationships are loaded."""
        if 'reldepth' in self.gosubdag.prt_attr['flds']:
            return "R{R:02}".format(R=goobj.reldepth)
        return "D{D:02}".format(D=goobj.depth)