def METHOD_NAME(self, fextractor_type):
    if self.feature_dict[fextractor_type] == 'all':
        fextractor_class = FeatureExtractor.find_subclass(fextractor_type)
        atom_features = fextractor_class.ATOM_FEATURES + getattr(fextractor_class, 'DERIVED_ATOM_FEATURES', [])
    else:
        atom_features = self.feature_dict[fextractor_type]
    return atom_features