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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 get_grouped_psf_model(template_psf_model, star_group, pars_to_set):
 """ Construct a joint PSF model which consists of a sum of PSF's templated on a specific model, but whose parameters are given by a table of objects. Parameters template_psf_model : `astropy.modeling.Fittable2DModel` instance The model to use for *individual* objects. Must have parameters named ``x_0``, ``y_0``, and ``flux``. star_group : `~astropy.table.Table` Table of stars for which the compound PSF will be constructed. It must have columns named ``x_0``, ``y_0``, and ``flux_0``. Returns ------- group_psf An `astropy.modeling` ``CompoundModel`` instance which is a sum of the given PSF models. """


    group_psf = None

    for star in star_group:
        psf_to_add = template_psf_model.copy()
        for param_tab_name, param_name in pars_to_set.items():
            setattr(psf_to_add, param_name, star[param_tab_name])

        if group_psf is None:
            # this is the first one only
            group_psf = psf_to_add
        else:
            group_psf += psf_to_add

    return group_psf