How to use the sherpa.utils.get_keyword_defaults function in sherpa

def get_plot_defaults():
    return get_keyword_defaults(plot, 7)

def get_split_plot_defaults():
    return get_keyword_defaults(_set_subplot, 3)

def __init__(self):
        self.priors = {}
        self._walker = Walk
        self._sampler = MetropolisMH
        self._sampler_opt = get_keyword_defaults(MetropolisMH.init)
        self.sample = None
        self.walk = lambda: None
        NoNewAttributesAfterInit.__init__(self)

def get_histo_defaults():
    return get_keyword_defaults(_histogram, 6)

def __init__(self):

        self.priors = {}

        # default sampler
        self.sampler = 'MetropolisMH'
        self.samplers = {
            'MH' : {
                'class' : MH,
                'opts' : get_keyword_defaults(MH.init)
                },

            'MetropolisMH' : {
                'class' : MetropolisMH,
                'opts' : get_keyword_defaults(MetropolisMH.init)
                },
            }

        self.walk = 'Walk'
        self.walks = {
            'Walk' : {
                'class' : Walk,
                },

def get_contour_defaults():
    return get_keyword_defaults(contour, 6)

def _set_sampler(self, sampler):
        self._sampler = sampler
        self._sampler_opt = get_keyword_defaults(sampler.init)

def get_contour_defaults():
    return get_keyword_defaults(contour, 6)