Some regions in Julich brain 1.18 mni152 statistical map is not reachable

[AhmetNSimsek]

Following regions cannot be fetched due to 404 from Julich brain 1.18 mni152 statistical map:

• Area ifs4 (IFS) left
• Area ifs4 (IFS) right
• Area ifs1 (IFS) left
• Area ifs1 (IFS) right
• Area ifs2 (IFS) left
• Area ifs2 (IFS) right
• Area ifs3 (IFS) left
• Area ifs3 (IFS) right
• Ventral Dentate Nucleus (Cerebellum) right

Since this is a SparseMap, the SparseIndex is calculated upon requesting any of the maps. But SparseIndex creation fails due to these regions and hence it fails to fetch any region. The PR FZJ-INM1-BDA/siibra-python#310 was suggested (the sparsemap class supports failures but parcellationmap.fetch fails the process) but this is a data issue.

[AhmetNSimsek]

@xgui3783, shall we contact Hartmut for this?