Post: #5

Regions are stored inside sectors as a inherited class from CGTypedArray.

For each new entry on this sector this array is being read checking if this region is overlapping with anyone else already added.

If not, region is added directly.

If yes, some checks are made:
- if region rects are equal -> return false (the error)
- if new region is inside the one being checked the loop continues.
- if checking region is a multi and new one is not, the loop continues.
- if still inside the loop (the other possible casses) then this region is added to the sector's list.

This is a 'fast' explanation of what happens, what will anwser your question, I think, is: 'above' region is last one added.