code: def _rebuildPartitionIdMap(self, partitionIdList):
      
      self._partitionIdMap = {}
      for row, partitionId in enumerate(partitionIdList):
        indices = self._partitionIdMap.get(partitionId, [])
        indices.append(row)
        self._partitionIdMap[partitionId] = indices
docs: Rebuilds the partition Id map using the given partitionIdList