docs: def get_source_qq_data(id=None):
      """Get data for a quantile-quantile plot of the source data and model.
  
      *id*
        The dataset id for which to get the data; defaults if unspecified.
      Returns:
        An ndarray of shape ``(3, npts)``. The first slice is the energy axis in
        keV; the second is the observed values in each bin (counts, or rate, or
        rate per keV, etc.); the third is the corresponding model value in each
        bin.
  
      The inputs are implicit; the data are obtained from the current state of
      the Sherpa ``ui`` module.
  
      """
      sdata = ui.get_data(id=id)
      kev = sdata.get_x()
      obs_data = sdata.counts
      model_data = ui.get_model(id=id)(kev)
      return np.vstack((kev, obs_data, model_data))