If [`amplitude`](https://unlockgnn.readthedocs.io/en/latest/modules/unlocknn.kernel_layers.html#unlocknn.kernel_layers.AmpAndLengthScaleFn._amplitude) and [`_length_scale`](https://unlockgnn.readthedocs.io/en/latest/modules/unlocknn.kernel_layers.html#unlocknn.kernel_layers.AmpAndLengthScaleFn._amplitude) should be public, we should remove the leading underscore. Otherwise they should be removed from the documentation.
If
amplitudeand_length_scaleshould be public, we should remove the leading underscore. Otherwise they should be removed from the documentation.