Serge Koudoro

Thank you for adding thoses icons @ganimtron-10. Merging

Can you rebase this branch? or resolve the conflicts Thanks

It seems to be used only to the life model: FiberFit [here](https://github.com/dipy/dipy/blob/master/dipy/tracking/life.py#L501). However, `self.data` is never called. So it does nothing, I think we can remove it safely to simplify...

I agree that is the most used pattern. However, I wonder what the `model_params` type could be? Sometimes a `list`, sometimes a `dict / tuple`, other times just a `parameter`....

Hi @arokem, Do you plan to clean a bit this PR before a review? is it still WIP? After a really quick look, I saw some `fvtk` so I suppose...

Also, could you fix [the pep8 issues](https://github.com/dipy/dipy/pull/2304#issuecomment-738482184)

Thank you for the update! @ShreyasFadnavis, Can you check this PR too? thank you

Also, Do you plan to use this opportunity to fix #1773 (option to invert the signal in DKI WMTI)?

Hi @arokem, Do you think you can finalize this for the next release, 1 week from now, or should I move it for the release in June?

ok, no problem, thanks!