'Refits the GEE model using a sequence of values for the
dependence parameters.
Parameters
dep_params_first : array-like
The first dep_params in the sequence
dep_params_last : array-like
The last dep_params in the sequence
num_steps : int
The number of dep_params in the sequence
Returns
results : array-like
The GEEResults objects resulting from the fits.'

def sensitivity_params(self, dep_params_first, dep_params_last, num_steps):

    model = self.model
    import copy
    cov_struct = copy.deepcopy(self.model.cov_struct)
    update_dep = model.update_dep
    model.update_dep = False
    dep_params = []
    results = []
    for x in np.linspace(0, 1, num_steps):
        dp = ((x * dep_params_last) + ((1 - x) * dep_params_first))
        dep_params.append(dp)
        model.cov_struct = copy.deepcopy(cov_struct)
        model.cov_struct.dep_params = dp
        rslt = model.fit(start_params=self.params, ctol=self.ctol, params_niter=self.params_niter, first_dep_update=self.first_dep_update, cov_type=self.cov_type)
        results.append(rslt)
    model.update_dep = update_dep
    return results
