`VarGetter.GetSlice` is useful only for 1 dimensional data

[redgis]

If a variable has data of multiple dimension, GetSlice will retrieve all the data of the slice of the first dimension.

Example : variable of dimensions time, latitude, longitude

GetSlice(0, 2) will retrieve the data for all latitude, longitude, for the time 0 and 1.

I am wondering how this API could be improved to allow slicing all dimensions.