def METHOD_NAME(self, df, **kwargs):
    '''Get an in-memory numpy array with the predictions of the LightGBMModel on a vaex DataFrame.
    This method accepts the key word arguments of the predict method from LightGBM.
    :param df: A vaex DataFrame.
    :returns: A in-memory numpy array containing the LightGBMModel predictions.
    :rtype: numpy.array
    '''
    # TODO: we want to go multithreaded/parallel/chunks
    return self.booster.METHOD_NAME(df[self.features].values)