def _linear_kernel_scale(kernel, mean, std, rescale):
    """Scale Gaussian kernel hyperparameters.

    Parameters
    ----------
    kernel : dict
        Dictionary containing all information for a single kernel.
    mean : array
       An array of mean values for all features.
    std : array
       An array of standard deviation values for all features.
    rescale : boolean
       Flag for whether to scale or rescale the data.
    """
    print('{} kernel hyperparameters left unscaled'.format(kernel['type']))
    return kernel
