def METHOD_NAME(self):
    unique_params = set()
    for element in self._target_elements:
        # grab element parameters
        for param in element.Parameters:
            if not param.IsReadOnly \
                    and param.StorageType == DB.StorageType.String:
                unique_params.add(param.Definition.Name)
        # grab element family parameters
        # if element.Family:
        #     for param in element.Family.Parameters:
        #         if not param.IsReadOnly \
        #                 and param.StorageType == DB.StorageType.String:
        #             unique_params.add(
        #                 'Family: {}'.format(param.Definition.Name)
        #                 )
    all_params = ['Name', 'Family: Name']
    all_params.extend(sorted(list(unique_params)))
    self.params_cb.ItemsSource = all_params
    self.params_cb.SelectedIndex = 0