lastCompletedOperation
The summarized completed map operation of the CompositeRegion.
A null
value means that no completed map operations are known or the current map operation is still in execution or waiting to be executed.
Performing a map operation on a CompositeRegion could result in multiple sub-sequenced map operations in execution or waiting to be executed. The lastCompletedOperation will be determined when all the sub-sequenced map operations of the CompositeRegion are finished.