def METHOD_NAME(self, locations, logger=None):
    """Predict from knn.
    :param locations:   The locations for interpolating. (n_samples, n_features).
                        In sklearn parlance, this is 'X'
    :returns:   Regressed parameters y (n_samples, n_targets)
    """
    logger = galsim.config.LoggerWrapper(logger)
    regression = self.knn.predict(locations)
    logger.debug('Regression shape: %s', regression.shape)
    return regression