from the code comment it sounds like this need to go now before the `super(GEE, self).__init__` call where the missing will be dropped.
maybe not, IX would contain the indices without nan-rows:
`self.data.missing_row_idx` is stored after the missing data check
I never looked at that part of the code in details and I'm not sure how it behaves.

IX should be a lower case name, `row_idx`, `row_indices` ?