def get_feature_names(self, features=None):
        """ Returns names of features. If features is None, returns all
        features. Otherwise assumes the user is trying to find the order of the
        features.  """
        if features:
            return self.feature_table.get_ordered_names(features)
        else:
            return self.feature_table.feature_names
Returns names of features. If features is None, returns all
        features. Otherwise assumes the user is trying to find the order of the
        features.