snippet16.txt

- (GO*) getAllMusicProgressCancellation:(ProgressCancellation)progressCancellation
{
    GO* go = [GO groupOperation:^(GO * _Nonnull groupOp) {
    
        void (^universalProgress)(DTO*, DTODownProgress) = ^(DTO* op, DTODownProgress p){
            if (groupOp.state == RXNO_Cancelled) [op cancel];
            if (progressCancellation) progressCancellation(groupOp);
        };
    
        DTO* op1 = [[DTO GET:url1 downloadProgress:universalProgress] syncStart];
        NSLog(@"op1: %@",[op1 stateDescription]);
        
        if (groupOp.state == RXNO_Cancelled) return;
        
        DTO* op2 = [[DTO GET:url2 downloadProgress:universalProgress] syncStart];
        NSLog(@"op2: %@",[op2 stateDescription]);
        
        groupOp.result   = @[op1.receivedData, op2.receivedData];
        group.resultClass = NSStringFromClass(NSArray.class);
    }];
    
    go.owner = [BO addressInMemory:self];
    return go;
}
     
 - (GO*) getAllVideoProgressCancellation:(ProgressCancellation)progressCancellation
 {
    ...   
 }