question: protected void applyPatch ( State current , State patch ) { if ( patch . taskInfo != null ) { ServiceUtils . logInfo ( this , "stage update: %s to %s" , current . taskInfo . stage , patch . taskInfo . stage ) ; current . taskInfo = patch . taskInfo ; } if ( patch . dataStoreCount != null ) { current . dataStoreCount = patch . dataStoreCount ; } if ( patch . finishedDeletes != null ) { current . finishedDeletes = patch . finishedDeletes ; } if ( patch . failedOrCanceledDeletes != null ) { current . failedOrCanceledDeletes = patch . failedOrCanceledDeletes ; } }
target:  Applies patch to current document state.