Args:
            numerical_feature_list: list of numerical features
            categorical_feature_list: list of categorical features

        Returns:
            Dictionary with following keys:
                features: DataFrame with concatenated features
                feature_names: list of features names
                categorical_features: list of categorical feature names

def transform(self, numerical_feature_list, categorical_feature_list):
        """
        Args:
            numerical_feature_list: list of numerical features
            categorical_feature_list: list of categorical features

        Returns:
            Dictionary with following keys:
                features: DataFrame with concatenated features
                feature_names: list of features names
                categorical_features: list of categorical feature names
        """
        features = numerical_feature_list + categorical_feature_list
        for feature in features:
            feature = self._format_target(feature)
            feature.set_index(self.id_column, drop=True, inplace=True)
        features = pd.concat(features, axis=1).astype(np.float32).reset_index()

        outputs = dict()
        outputs['features'] = features
        outputs['feature_names'] = list(features.columns)
        outputs['categorical_features'] = self._get_feature_names(categorical_feature_list)
        return outputs